2026-2027 new C165 IN DEPTH STUDY GUIDE PRE-ASSESSMENT BASED Integrated Physical Sciences with answe

2026-2027 new C165 IN DEPTH STUDY GUIDE PRE-ASSESSMENT BASED Integrated Physical Sciences with answers explained Western Governors University

✓ Index/Overview of C165 PA Questions by Sec s Topic: Pages 1-4 ⬛ ✓ Questions Breakdown s Thorough Explanations Start on Page: 5 ⬛ *Questions that aren’t in this guide but ARE in the PA are about Terrestrial Planets, Asteroid Belt, Inelastic Collisions, Renewable Resources- Please see the last couple of pages for these topic summaries*

:_ 1. Scientific Reasoning & Models H •

✓ Difference between law, theory, hypothesis, observation, inference ⬛

•

✓ What makes a scientific model reliable (evidence, prediction, revision) ⬛

•

✓ How science responds to new evidence (revise theory, investigate contradiction) ⬛

•

⬛ Controlled experiments vs observational questions ✓

● 2. Earth & Space Science l •

✓ Plate tectonics: causes of volcanoes & earthquakes, boundary types ⬛

•

✓ Rock cycle: identify igneous, sedimentary, metamorphic, how they form ⬛

•

✓ Stratigraphy: law of superposition, intrusions, fossil evidence ⬛

•

✓ Water cycle: terms like precipitation, runoff, infiltration ⬛

•

✓ Atmosphere layers (troposphere = weather, stratosphere = ozone) ⬛

•

✓ Seasons & Earth's tilt — when is it summer/winter in hemispheres? ⬛

•

✓ Solar system: location of asteroids, terrestrial vs gas planets ⬛

•

⬛ Natural vs human-caused climate change ✓

⬛ 3. Chemistry •

⬛ Atoms: protons, neutrons, electrons ✓

•

✓ Ions: what they are, charges, cations vs anions ⬛

•

✓ Types of bonds: ionic (transfer), covalent (share), metallic (sea of electrons) ⬛

•

✓ States of matter: solid, liquid, gas ⬛

•

⬛ Phase changes: endothermic (melting, boiling), exothermic (freezing, condensing) ✓

•

⬛ Law of conservation of matter: mass stays the same in chemical changes ✓

•

✓ Mixtures vs Compounds: mixtures can be separated physically ⬛

⬛ 4. Physics & Forces ç̆ l

ç' C

•

✓ Newton's Laws (especially 1st & 2nd: inertia, F = ma) ⬛

•

✓ Force and motion: acceleration, mass effect on movement ⬛

•

✓ Friction: what it is, how it affects motion (ex: pencil on paper) ⬛

•

✓ Elastic vs inelastic collisions ⬛

•

✓ Types of waves: sound (mechanical, needs medium) vs light (EM, vacuum) ⬛

•

✓ Energy transformations: potential ⬛t kinetic ⬛

•

✓ Renewable energy sources: solar, wind, hydro, geothermal, biomass ⬛

5. Test Strategy Tips •

† Watch out for: ► ) o

Words like "always", "never", "best explanation"

o

Misleading scientific-sounding answers (e.g., “nuclear force between ions” = wrong)

•

" If it's a prediction question, think: “what can be tested?” ^

•

⬛“ Don’t overthink! Trust your study.

M̈ ¡ Final Mindset ' -

"^

•

≈ You’ve studied hard — you know this.

H

•

z· Use your time wisely: mark confusing ones, return later. ●

•

-̂ Breathe deep, read carefully. }

SECTION 1 – Scientific Investigation s Motion

¸?•Ç Scientific Process and Inquiry •

Q1 – Physics model (Scientific disciplines)

•

Q2 – Chemistry C Earth Science (Disciplines in environmental science)

•

Q3 – Hurricane energy (Earth Science + Physics)

•

Q4, Q5, Q6 – Controlled Experiments

•

Q7 – Scientific Law (Newton’s Law of Gravity)

•

Q8 – Scientific Theory (Plate Tectonics)

•

QG – Hypothesis (Dissolving sugar)

• Y

Q10–Q14 – Scientific reasoning C theory change

Newton’s Laws s Forces •

Q15 – Newton's 3rd Law (Pushup example)

•

Q16–Q18 – Newton's 2nd Law (Mass and force)

•

Q1G – Inertia C Braking force

•

Q20–Q23 – Friction and Gravity

f Energy s Motion ) •

Q24–Q27 – Energy transformations (Elastic, chemical, thermal, kinetic)

•

Q28–Q31 – Electromagnetic radiation (waves)

•

Q32 – Longitudinal wave = Sound

•

Q33 – Electromagnetic wave characteristics

"^

SECTION 2 – Chemistry of Matter

{ ~

Matter, Atoms, and Compounds •

Q34 – Electron (Outside nucleus)

•

Q35 – Neutron (No charge)

•

Q36 – Mixture (Cookie)

•

Q37 – Compound (NaCl)

States and Changes of Matter •

Q38 – Liquids

•

Q3G – Liquid to gas

•

Q40 – Chemical change (Egg)

•

Q41 – Covalent bonds

•

Q42 – Group 2 properties

•

Q43 – Similar elements (Na/K)

•

Q44–Q45 – Conservation of Mass

•

Q46 – Chemical reaction C mass (Baking soda + vinegar)

•

Q47–Q48 – Energy absorption and phase change (Evaporation)

?● SECTION 3 – Earth s Space Science Ç Universe and Solar System Y

•

Q4G – Gravity forming Earth

•

Q50 – Gravity forming galaxies

●l Seasons, Earth's Movement •

Q51–Q53 – Earth's orbit, seasons, position

) Plate Tectonics s Rock Cycle „5 •

Q54–Q56 – Plate boundary risks

•

Q57–Q58 – Landforms (Valley, Meander)

•

Q5G–Q60 – Rock cycle processes

•

Q61–Q62 – Geologic history

🌦 Atmosphere, Weather s Climate •

Q63–Q64 – Atmospheric layers (Troposphere)

•

Q65–Q66 – Water cycle (Precipitation, Runoff)

•

Q67–Q68 – Fronts and pressure systems (Weather changes)

•

Q6G – Natural climate change (Dust Bowl)

•

Q70 – Human-caused climate change (CO₂)

^ Question 1 " •

✓ “Taught by Chat GPT Sec 1” document ⬛

•

⬛ “Sec 1 Note Taking Guide” document ✓

•

? Question: A mathematical model is used to predict the trajectory of a bullet •¸Ç fired from a gun. Which discipline of physical science is used to develop this model?

•

✓ Answer: Physics ⬛

◉’ Topic: Scientific Models s Physical Science Disciplines (Section 1.1) ●

: What Are Physical Sciences? _H In the “Sec 1 Note Taking Guide”, Section 1.1 explains that physical science is a broad branch of science that deals with non-living systems. It includes: •

Physics (motion, forces, energy)

•

Chemistry (matter and reactions)

•

Earth Science (geology, meteorology)

•

Astronomy (space and celestial bodies)

Each of these fields contributes different tools and methods to understanding the natural world.

L□] From the “Taught by Chat GPT Sec 1” doc: It states that physics is concerned with the study of matter, energy, motion, and forces. It uses mathematical models and experiments to make predictions about how the world behaves.

k

What Is a Mathematical Model?

A mathematical model is: •

A way to represent a real-world process using math, equations, or simulations.

•

Used to predict future behavior or understand complex systems.

In this case: •

The trajectory of a bullet refers to its path through space after being fired.

•

Predicting this path requires: o

Equations of motion (how position changes over time)

o

Understanding gravity (pulling the bullet downward)

o

Air resistance (slowing the bullet)

" Why Physics? ^ Physics is the correct discipline here because: •

It uses Newton’s Laws of Motion to model the bullet’s movement.

•

It calculates:

•

o

Initial velocity (how fast it leaves the gun)

o

Angle of launch

o

Acceleration due to gravity

o

Effects of air resistance

These components form a mathematical equation (or model) that predicts where the bullet will go and when it will hit a target.

✓ Summary Breakdown: ⬛ Component

Explanation

Question

What science develops models for bullet trajectories?

Component

Explanation

Correct Discipline

Physics

Why?

Physics explains motion, force, energy, and uses equations to model real-world actions like projectile motion.

What Is Used?

Newton’s Laws, gravity, vectors, initial velocity—all tools from physics.

Real-World Example

Ballistics experts use these models to analyze crime scenes or design safer firearms.

'çC

Bonus Thought:

This question introduces how interdisciplinary science works. While physics is central here, technology (software models), engineering (gun design), and math (equations) also play a role—but physics is the scientific core. " ^

Question 2

Question: An environmental scientist monitors pollutants in a lake.

Answer: Chemistry and Earth Science Topic: Disciplines of Physical Science (Section 1.1) Explanation: The environmental scientist is combining chemistry (studying substances and reactions) with Earth science (studying ecosystems, soil, water, and air).

● Topic: Physical Science Disciplines (Section 1.1) ?

L□ According to the “Taught by Chat GPT Sec 1” doc: ] The four key branches of physical science are: 1. Physics – forces, motion, energy 2. Chemistry – structure and reactions of matter 3. Earth Science – the Earth’s systems (lithosphere, hydrosphere, atmosphere) 4. Astronomy – space, celestial objects Environmental science often pulls from both chemistry and Earth science.

.]

According to the “Sec 1 Note-Taking Guide”:

It highlights that: •

Earth science focuses on natural systems like weather, rocks, oceans, and Earth's structure.

•

Chemistry helps understand how substances behave, interact, or change in nature (like pollutants dissolving, reacting, or settling in lakes or rivers).

:_H Real-World Application In the case of pollutants in a lake, the scientist needs to answer: •

What is in the water?

•

How much of it is there?

•

How will it move, settle, or spread?

•

What chemical reactions might take place in the lake?

This requires: ➤ Chemistry to: •

Identify the pollutants (e.g., heavy metals, nitrates)

•

Understand chemical interactions (e.g., acid rain or toxic runoff)

•

Measure concentrations and reactions in water

➤ Earth Science to:

ç' C

•

Analyze lake systems (hydrology)

•

Understand sedimentation, erosion, and runoff patterns

•

Predict how pollutants will travel through water, soil, and ecosystems

Why Both Disciplines?

Chemistry

Earth Science

Studies the composition and reactions of Studies natural systems like lakes, rivers, and pollutants

ecosystems

Determines if the pollutant is acidic, basic, toxic

Explains how pollutants spread through water and affect land

Used to monitor safe drinking water

Used to evaluate ecosystem health

⬛ ✓ Summary Breakdown: Component

Explanation

Question Focus

Studying pollutants in a lake

Disciplines Involved

Chemistry and Earth Science

Why Chemistry?

To identify and measure pollutants and chemical reactions

Why Earth Science? To understand how pollutants affect water systems and ecosystems Scientific Skill Set

Data collection, water testing, geographic modeling, chemical analysis

’ Real Example: • “ ˛ 3 A lake experiencing algal blooms (due to fertilizer runoff) would require:

£̂ Ç

•

Chemistry to test nitrate levels and understand chemical causes of blooms

•

Earth Science to analyze land runoff patterns and how the lake's system is disrupted

Question 3

Question: Which study involves both Earth science and physics?

Answer: Calculating how much energy is associated with a hurricane Topic: Energy & Interdisciplinary Science (Section 1.1 and 1.8 + Section 3.7) Explanation: Hurricanes are natural systems (Earth science) powered by massive

transfers of energy, heat, and motion (physics). Understanding them requires both disciplines.

C Interdisciplinary Science: Earth Science + Physics ç ' This question highlights how scientific investigations often combine multiple disciplines to understand complex natural phenomena—like hurricanes, which are both physical and planetary events.

L] From the “Taught by Chat GPT Sec 1” doc: □ •

Physics helps explain how energy moves—in the form of heat, motion (kinetic), and waves.

•

Earth Science covers weather, climate, and atmospheric systems like hurricanes.

To understand a hurricane:

].

•

You need Earth science to track, describe, and model the hurricane's structure (pressure systems, wind patterns, cloud formation).

•

You need physics to calculate energy: temperature differentials, kinetic energy in wind, and heat from water vapor.

From the “Sec 1 Note Taking Guide”: •

Section 1.8 explains energy types and transformations, which are essential to hurricane dynamics: o

Warm ocean water provides thermal energy

o

Rising warm air converts thermal to kinetic energy (wind)

o

Energy is also released as latent heat when water vapor condenses

f So, What Energy Are We Calculating? µ ˛ Scientists estimate that a mature hurricane releases ~5×10¹⁹ joules per day, mostly from:

•

Latent heat energy released as water vapor condenses

•

Kinetic energy in the hurricane’s high-speed winds

Physics equations involved include: •

KE = ½mv² (Kinetic energy)

•

Q = mcΔT (Heat energy)

?● Why Earth Science?

Hurricanes are:

" ^

•

Weather events in the troposphere

•

Tracked using satellite and radar systems

•

Influenced by global Earth systems like: o

Ocean currents

o

Atmospheric pressure zones

o

Earth's rotation (Coriolis effect)

Why Physics?

To calculate the energy in a hurricane, physicists must: •

Use equations of thermal energy transfer

•

Analyze kinetic energy of wind systems

•

Model fluid dynamics of the storm (air and water)

+ Why the other choices are incorrect: Option

Why It’s Incorrect

B. Measuring the energy produced by a generator

This is physics only, specifically electromagnetism and energy conversion (mechanical to electrical). It doesn't involve Earth science.

Option

Why It’s Incorrect

C. Comparing the composition of crude oil from different regions

This is a chemistry-based study (analyzing molecular makeup), possibly involving geology (if about rock layers), but not physics or energy directly.

D. Monitoring changes in phosphorus levels of a lake

This falls under environmental science and chemistry (nutrient cycling, pollution), but not physics. Also, phosphorus levels relate to water quality, not forces or energy.

✓ Summary Breakdown: ⬛ Component

Explanation

Topic

How much energy a hurricane releases

Disciplines

Earth Science and Physics

Earth Science Role

Studies weather systems, atmospheric patterns, and ocean interactions

Physics Role

Calculates energy transformation, wind motion, and heat transfer

Key Concepts

Kinetic energy, thermal energy, latent heat, fluid motion

Ç Real-World Application: Lç7 Meteorologists use satellite data, sea surface temperatures, and wind speeds to estimate hurricane strength and predict impact. They rely on physics for energy calculations and Earth science to interpret environmental conditions. ^ Question 4 " Question: Which question could be answered with a controlled experiment?

Answer: Does ice melt faster in an empty glass or in a glass full of water?

Topic: Controlled Experiments (Section 1.1) Explanation: This question tests the effect of one variable—the presence of water—on a measurable outcome—melting speed. It fits the definition of a controlled experiment, where all other conditions are held constant.

: What Is a Controlled Experiment?

H _ From the “Taught by Chat GPT Sec 1” doc: A controlled experiment is designed to test the effect of a single independent variable by holding all other variables constant.

From the “Sec 1 Note Taking Guide”: •

Independent Variable = the factor you change (e.g., presence of water)

•

Dependent Variable = what you measure (e.g., time it takes ice to melt)

•

Controlled Variables = what stays the same (e.g., size of the glass, amount of ice, room temperature)

¿● Why This Is a Controlled Experiment: Glass A

Glass B

Ice only (empty glass) Ice in a glass filled with water By comparing how fast the ice melts in each, and ensuring everything else is the same, we’re isolating the effect of water vs. air as the surrounding medium.

HO•Breakdown of the Scientific Method: Step

Description

Observation Ice melts faster in some settings Question

Does ice melt faster in water than in air?

Hypothesis

Ice melts faster in water because water transfers heat more efficiently than air

Experiment Two glasses, same ice, one with water, one without Data

Time until ice is fully melted

Step

Description

Conclusion Supports or refutes the hypothesis

↓n Scientific Concepts at Work: ' •

Heat transfer is more efficient in liquids than gases. o

•

Water has a higher heat capacity and conductivity than air.

So, ice in water will likely melt faster, not because water is warmer, but because it transfers heat better.

✓ Summary Breakdown: ⬛ Component

Explanation

Question

Does water make ice melt faster than air?

Correct Answer

This is answerable via a controlled experiment

Independent Variable

What surrounds the ice (air vs. water)

Dependent Variable Time it takes the ice to melt Why It’s Controlled

Everything else (amount of ice, container, temperature) stays the same

Key Scientific Idea

Heat transfer and experimental design

3 ’•“˛

Real-World Connection:

Controlled experiments like this are fundamental in chemistry and physics, but also in fields like food science (e.g., testing thawing rates), climate science, and engineering.

The ability to isolate a variable and measure its effects is at the heart of good science.

Question 5

Question: Which topic would be appropriate for a controlled experiment?

Answer: Determining how fast different chemical pollutants dissolve in water Topic: Controlled Experiments & Chemistry (Section 1.1 & 2.2) Explanation: This question asks about the rate of dissolution of various pollutants, which can be tested experimentally by changing only the type of chemical while keeping other variables constant. This is a classic example of a controlled experiment in chemistry.

" From the “Taught by Chat GPT Sec 1” document: ^ It defines a controlled experiment as one in which: •

You manipulate one variable (independent variable)

•

You measure one outcome (dependent variable)

•

You hold everything else constant

Also, it highlights that chemistry studies how substances behave, including:

_Ĵ

•

Solubility (how well things dissolve)

•

Reaction rates

•

Concentration and saturation

From the “Sec 1 Note Taking Guide”: •

Controlled experiments are key to identifying causal relationships.

•

In this case: o

Independent Variable = type of chemical pollutant

o

Dependent Variable = how quickly it dissolves in water

o

Control Variables = water temperature, volume, agitation (stirring), amount of chemical

▼%¡ Example Experimental Setup: ' : Imagine testing 3 pollutants: nitrate, phosphate, and mercury chloride.

You would:

1. Use identical beakers with equal amounts of water at the same temperature.

2. Add the same mass of each pollutant into separate beakers.

3. Stir at the same rate or leave them still.

4. Record how long it takes each to dissolve completely, or how much dissolves after a set time.

By keeping everything except the pollutant constant, the experiment is controlled.

_ :H

'çC

Why It’s Chemistry + Experimental Design: •

Chemistry studies how substances interact with solvents like water.

•

Understanding pollutant behavior helps in: o

Environmental cleanup

o

Water quality monitoring

o

Public health risk assessment

Related Scientific Concepts:

Concept

Description

Solubility

How much of a substance can dissolve in a liquid

Dissolution Rate

How fast a substance dissolves

Controlled Variables Things that must stay the same to ensure valid results Experimental Validity The accuracy and reliability of the experiment’s outcome

⬛ Summary Breakdown: ✓ Component

Explanation

Question Type

Controlled experiment setup

Component

Explanation

Correct Setup

Test different pollutants with all other conditions the same

Discipline

Chemistry, under physical science

Key Science

Solubility, rate of reaction, heat and mass transfer

Why It’s Controlled

Only one variable (pollutant type) is changed; everything else is constant

?● Real-World Applications:

" ^

•

Environmental chemistry uses this approach to determine how quickly pollutants enter drinking water systems.

•

Helps inform regulations on safe chemical usage and waste disposal.

•

Used by EPA, water treatment labs, and scientific researchers.

Question 6

Question: Which question requires a controlled experiment to answer?

Answer: ⬛ ✓ Which type of rock contains the most calcium?

Topic: Controlled Experiments & Earth Science (Section 1.1 & 3.5) Explanation: This question involves comparing types of rock while measuring calcium content, which is testable by changing one variable (rock type) and measuring an outcome (amount of calcium). This fits the format of a controlled experiment.

Jˆ_ Breakdown of the Choices: Option

Why It Does or Does Not Require a Controlled Experiment

⬛ Which type of rock ✓ contains the most calcium?

✔ Requires testing different rock types under the same conditions, making it a classic controlled experiment.

+ Which planet has the most ✖ Requires observational astronomy, not moons? experimentation. It's a factual count, not an experiment.

Why It Does or Does Not Require a Controlled Experiment

Option

+ Which elements are found ✖ Involves sample analysis (observational chemistry), not manipulation of variables. in Earth’s atmosphere? + Which fossils formed earliest in Earth’s history?

✖ Answered using fossil records and radiometric dating (geological observation), not experimentation.

H_ Why “Which type of rock contains the most calcium?” is Experimental: : This question fits the controlled experiment structure: •

Independent Variable: Type of rock (limestone, sandstone, granite, etc.)

•

Dependent Variable: Amount of calcium found

•

Controlled Variables: Mass of rock sample, testing procedure, equipment, temperature

You could: 1. Collect equal-sized samples of various rock types.

2. Use acid tests, flame tests, or spectroscopy to measure calcium content.

3. Compare results to determine which rock contains the most calcium.

This makes it a valid, testable question using the scientific method.

⬛“ How the Scientific Method Applies: Step

Example in This Context

Question

Which rock has the most calcium?

Hypothesis

Limestone contains more calcium than granite.

Experiment

Test different rocks, keeping other variables constant.

Data Collection Measure calcium content using lab techniques.

Step

Example in This Context

Conclusion

Determine which rock has the highest calcium levels.

⬛ Summary Breakdown: ✓ Component

Explanation

Correct Answer ⬛ ✓ Which type of rock contains the most calcium?

Why?

It’s testable with a controlled experiment: you vary one thing (rock type) and measure one thing (calcium content)

Scientific Discipline

Earth Science + Chemistry

Method

Controlled experiment using chemical analysis

Other Choices

Require observations or data analysis, not experiments

Y

Question 7 (Corrected)

Question: Sir Isaac Newton discovered that the force of gravity between two masses increases if the masses increase, and decreases if the distance between the masses increases. No experiments have ever contradicted this relationship. Which type of scientific statement is this?

Answer: ⬛ ✓ Law Topic: Scientific Laws vs. Theories vs. Hypotheses (Section 1.2) Explanation: This statement is a scientific law because it describes a consistently observed natural relationship using mathematical terms and has never been contradicted by experiment.

□L] Based on the “Taught by Chat GPT Sec 1” and “Sec 1 Note-Taking Guide”: ˛ Scientific Laws: “ ’• 3 •

Describe what happens in nature under certain conditions

•

Are based on repeated observations and mathematical relationships

•

Do not explain why something happens — they just describe it

•

Are widely accepted and consistently confirmed by experiments

✓ Example: Newton’s Law of Universal Gravitation ⬛ F=Gm1m2r2F = G \frac{m_1 m_2}{r^2}F=Gr2m1m2 This law describes the gravitational force (F) between two masses (m₁ and m₂) separated by a distance (r).

It doesn’t explain why gravity works — it just describes how it behaves in every tested case.

ić!:f

How It's Different from a Theory, Hypothesis, and Inference:

Term

Definition

Why It’s Not the Right Answer

Hypothesis

A testable prediction based on observation

Newton’s statement isn’t a guess— it’s well-established and tested

Theory

An explanation for why something happens, based on evidence

Newton’s Law describes what happens, not why gravity exists

A logical conclusion based on

Newton’s Law is not a subjective

evidence

interpretation—it’s measurable and universal

A concise, universally accepted statement describing a consistent natural phenomenon

✔ Correct — this fits Newton’s formula for gravity exactly

Inference

⬛ Law ✓

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer ⬛ ✓ Law Why? Does it explain why?

It’s a universally observed, mathematical description of gravitational behavior + No — laws describe “what,” not “why”

Component

Explanation

How is it confirmed?

Through repeated experiments and measurements that never contradict it

Example

Newton’s Law of Universal Gravitation: F=Gm1m2r2F = G \frac{m_1 m_2}{r^2}F=Gr2m1m2

C Bonus Tip: ç ' Laws describe. Theories explain. Hypotheses predict. Inferences interpret.

This is a useful way to mentally sort these terms for C165 and beyond! ? Question 8 ● Question: The well-accepted scientific explanation for many characteristics of Earth's crust states that the crust is broken into several large plates. These plates move slowly over the mantle below because of convection and other processes. Earthquakes and volcanoes are most common at places where the plates interact. Evidence from physics, chemistry, and geology supports this explanation.

Which type of scientific idea is this explanation an example of?

Answer: ✓ ⬛ Theory Topic: Scientific Theories – Explanation with Broad Evidence (Section 1.2) Explanation: This is an example of a scientific theory because it explains why and how Earth's crust behaves, is supported by multiple lines of evidence, and is widely accepted by the scientific community.

]L From the “Taught by Chat GPT Sec 1” s “Sec 1 Note-Taking Guide”: □ : What Is a Scientific Theory? _H A scientific theory is: •

A well-substantiated explanation of some aspect of the natural world

•

Supported by evidence from repeated testing and observation

•

Based on data from multiple scientific disciplines

•

Able to explain relationships and mechanisms (how something works)

•

Open to revision with new evidence

This specific case describes the: Theory of Plate Tectonics It explains:

Y

•

That Earth’s crust is divided into plates

•

These plates move due to convection currents in the mantle

•

This movement causes earthquakes, mountain building, and volcanoes

•

The theory is supported by physics (seismic data), chemistry (mantle composition), and geology (rock strata, fossil distribution)

Why It’s a Theory and Not the Other Options:

Term

Definition

Hypothesis A tentative, testable idea

Why It’s NOT Correct Here This is already well-established and supported by years of evidence

Law

A description of what happens in nature, usually mathematical

A law describes what happens (e.g., gravity), not why or how like this theory does

Prediction

A specific outcome you expect from a hypothesis or theory

The statement is an explanation, not a forecast of future events

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer ⬛ ✓ Theory Why?

It explains why and how Earth’s crust moves, and is supported by broad, interdisciplinary evidence

Component

Explanation

Discipline

Earth Science, Physics, Chemistry, Geology

Real-World Example

Theory of Plate Tectonics — one of the central unifying theories in Earth science

Key Difference

Theories explain; laws describe; hypotheses predict; predictions forecast

●? Real-World Significance: Plate tectonics explains: •

Why earthquakes cluster along faults (like the San Andreas)

•

Why volcanic chains form near subduction zones

•

How continents have drifted (continental drift evidence from fossils, paleoclimate, rock formations)

This makes it a powerful explanatory framework—a hallmark of a scientific theory. ´'E3

Question G

Question: A student proposes that sugar will dissolve faster in rubbing alcohol than in water. The student reasons that sugar and rubbing alcohol both contain carbon so they will mix more easily.

Which type of scientific idea is the student's proposal an example of?

Answer: ⬛ ✓ Hypothesis Topic: Scientific Method – Forming Hypotheses (Section 1.1 & 1.2) Explanation: The student's idea is a testable explanation based on prior reasoning. It makes a prediction and suggests a reason why the outcome might occur, which makes it a clear example of a hypothesis.

^" What Is a Hypothesis?

From the “Taught by Chat GPT Sec 1” and the “Sec 1 Note-Taking Guide”, a hypothesis is:

•

A testable and falsifiable statement or prediction

•

Based on prior knowledge, reasoning, or observation

•

Usually written in an “If... then...” or explanatory format

•

Serves as the foundation for an experiment

Jˆ_ Why This Is a Hypothesis: In the student’s statement: •

They are proposing an idea that can be tested:

Sugar dissolves faster in rubbing alcohol than in water.

•

They are offering a rationale:

Because both sugar and rubbing alcohol contain carbon.

•

The student could design an experiment to test this idea.

That fits the definition of a hypothesis exactly.

' çC

Let’s Compare It to the Other Options:

Choice

Definition

Why It’s Incorrect Here

⬛ ✓ Hypothesis

A testable prediction based on reasoning or observation

✔ This is the best match

Theory

A broad, well-supported explanation of phenomena

✖ This is just a single idea, not supported by extensive data

Law

A description of a consistent natural relationship (often mathematical)

✖ This isn’t a proven, universal relationship

Observation

A direct recording of something seen or measured

✖ The student is making a prediction, not reporting data

✓ Summary Breakdown: ⬛

Component

Explanation

Correct Answer

⬛ ✓ Hypothesis

Why?

It’s a testable prediction based on the idea that sugar and alcohol both contain carbon

Scientific Method Step

Hypothesis formation (comes before experimentation)

What’s Next?

The student would run an experiment to confirm or refute their hypothesis

" ^

Real-World Example of This Process:

Let’s say the student runs a simple experiment: 1. Add equal amounts of sugar to identical amounts of rubbing alcohol and water.

2. Stir them both for the same amount of time.

3. Observe which dissolves faster.

4. Record and analyze results.

If the sugar dissolves faster in one, they can use this data to support or reject their hypothesis. This is the heart of scientific testing. ●l Question 10 Question: Why was the shrinking Earth idea replaced by the theory of plate tectonics?

Answer: ✓ ⬛ Plate tectonics explained observations about Earth that the shrinking Earth idea could not explain.

Topic: Nature of Science – How Scientific Theories Change (Section 1.2) Explanation: Scientific theories are replaced when new evidence emerges that better explains observations. The plate tectonics theory provided a more comprehensive explanation than the outdated shrinking Earth hypothesis, so it became the accepted model.

Cç' Understanding the Scientific Shift _ :H

The Shrinking Earth Hypothesis: •

Claimed that Earth was cooling and contracting over time, causing the crust to wrinkle and form mountains.

•

Could not explain:

•

o

Matching fossils across continents

o

Magnetic striping on the ocean floor

o

Distribution of earthquakes and volcanoes

It was a limited explanation that couldn’t accommodate growing evidence

●? Plate Tectonics Theory: •

Introduced in the mid-20th century

•

States that Earth’s lithosphere is divided into plates that float and move over the asthenosphere due to convection currents in the mantle

•

Explained: o

Continental drift (fossil and rock matches across oceans)

o

Seafloor spreading (mid-ocean ridges)

o

Earthquake and volcano patterns

o

Mountain formation at plate boundaries

Because it accounted for all these observations, it replaced the older theory.

L]□ From “Taught by Chat GPT Sec 1” and “Note-Taking Guide”: •

Section 1.2 emphasizes that scientific theories change when new evidence emerges that can better explain observations.

•

This is a hallmark of the self-correcting nature of science:

When a new model fits the data better, it replaces older, weaker explanations.

+ Why the Other Answers Are Incorrect: Option

Why It’s Incorrect

+ New doesn’t automatically mean better — Plate tectonics was a new theory, reliability depends on explanatory power and which made it more reliable. evidence Geologists voted on which theory + Science doesn’t work by vote — it’s based on data to accept. and reasoning, not popularity Many well-known geologists proposed plate tectonics.

+ The authority of scientists doesn’t make a theory correct — only evidence does

⬛ ✓ Summary Breakdown: Component Correct Answer

Explanation ⬛ Plate tectonics explained observations that shrinking Earth could not ✓

Key Idea

Scientific theories are replaced when a better explanation becomes available

What Changed?

Evidence from geology, oceanography, and physics supported plate tectonics

Why It Matters Science progresses by refining models to reflect new data

¸?• Ç

Real-World Impact:

The theory of plate tectonics became one of the cornerstones of modern Earth science, changing how we understand: •

Earthquakes

•

Volcanoes

•

Mountain formation

•

Ocean floor spreading

•

Natural disaster prediction and modeling

S Question 11 ’F Question: Astronomers have long accepted that plate tectonics exists nowhere in our solar system except on Earth. In 2011, a scientist analyzed 100 NASA-space-mission photographs of Valles Marineris on Mars, the longest known series of canyons in the solar system. The scientist found that Valles Marineris showed features found only in locations on Earth where major tectonic plates divide.* What would be the appropriate response of scientists to this information?* Answer: ⬛ ✓ Carry out further research to gain more understanding of possible plate tectonics on Mars Topic: Nature of Science – Scientific Process & Openness to New Evidence (Section 1.2) Explanation: In science, when new observations emerge that challenge accepted understanding, the correct response is not to reject or vote, but to investigate further through research and evidence-gathering. Science is a self-correcting, evidence-based process.

ić!:f

Scientific Principles at Work:

From the “Taught by Chat GPT Sec 1” doc and “Sec 1 Note-Taking Guide”, Section 1.2 outlines the following principles: : Science Is: _H •

Based on evidence, not opinion or authority

•

Open to revision when new observations emerge

•

Driven by experimentation, observation, and peer review

•

Not political or decided by voting or reputation

So, in this case, scientists should follow up on the Mars canyon evidence with: •

More imaging and mapping

•

Seismic data (if available in the future)

•

Geologic modeling of Martian crust

•

Comparison to tectonic boundaries on Earth

This aligns with the scientific method: make observations → form hypotheses → test → draw conclusions → revise understanding as needed.

+ Why the Other Answers Are Incorrect: Answer Choice

Why It’s Wrong

+ Reject plate tectonics on Mars because it contradicts accepted science

Ignores science’s openness to new evidence — science doesn’t reject ideas without investigation

+ Decide based on the reputation of scientists involved

Science values data, not authority

+ Hold public debates and vote on it

Science is not democratic — it's based on evidence, not consensus by vote

⬛ ✓ Summary Breakdown: Component

Explanation

Correct Answer

✓ Carry out further research to gain more understanding of possible ⬛ plate tectonics on Mars

Why?

New evidence should be tested further, not dismissed or accepted without investigation

Key Scientific Values

Openness to new data, reliance on the scientific method, evidence > authority

Real-World Connection

Similar processes have led to discoveries like water on Mars, exoplanets, and gravitational waves

ç' C

Final Insight:

Science is dynamic and evidence-driven.

When new data challenges what we think we know, the scientific community asks:

“What does the evidence say?” — not “Who said it?” or “What did we used to believe?” )„5

Question 12

Question: According to the theory of plate tectonics, volcanoes are especially likely to form along plate boundaries because of rising magma. New satellite data mapping the ocean ffoor reveals thousands of seamounts, which are small volcanoes. Some of the seamounts are in lines that could correspond to past or present plate boundaries, but many are not aligned in this way.

How should scientists appropriately respond to the idea that some new mechanism of forming the volcanoes is involved?

Answer: ⬛ ✓ Carry out more research to understand better how the seamounts form Topic: Nature of Science – Responding to New Evidence (Section 1.2) Explanation: Science is evidence-driven and open to revision. When new observations (such as unaligned seamounts) don't fully match current theories, the appropriate response is to investigate further. This allows scientists to refine, expand, or adjust theories based on new data.

_: Key Scientific Principle: H From the “Taught by Chat GPT Sec 1” and “Note-Taking Guide”, Section 1.2 highlights that: ➤ Theories are not unchangeable truths. ➤ They can be modified or expanded as new evidence emerges.

Plate tectonics is a well-supported theory, but that doesn't mean it's the final word on all volcanic activity. The discovery of seamounts not aligned with plate boundaries suggests: •

There might be another mechanism of volcano formation (e.g., hot spots or mantle plumes)

•

These findings could enhance the current theory — not necessarily disprove it

✓ Why "Carry out more research" is the right answer: ⬛ •

Encourages scientific inquiry based on new observations

•

Supports the self-correcting nature of science

•

Allows for development of new models or expansion of existing theories

•

Keeps science evidence-based, not reliant on authority or opinion

+ Why the Other Answers Are Incorrect: Option

Why It’s Incorrect

+ Reject it because it contradicts plate tectonics

Science must explore anomalies, not ignore them.

Rejection without study is anti-scientific.

+ Accept it if the proposer is a Scientific acceptance is based on evidence, not credible expert reputation. + Stage public debates to get Science is not determined by public opinion or voting — it’s built on data, replication, and peer review. a consensus

ÇL Real-World Scientific Process: ç7 This scenario is very realistic. For example: •

Hawaiian Islands are formed by a hot spot — a plume of magma that stays fixed while the plate moves over it

•

Iceland has volcanic activity both at a divergent boundary and due to a mantle plume

These discoveries helped broaden the theory of plate tectonics — not disprove it.

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ Carry out more research to better understand how the seamounts form

Component

Explanation

Why?

New data challenges current explanations; science advances by exploring these anomalies

Core Scientific Value

Openness to new ideas supported by evidence

What Happens Next?

Further observation, hypothesis formation, controlled experiments or modeling, peer review

Related Disciplines

Geology, oceanography, geophysics, volcanology

Science is never finished — it evolves with each new discovery.

The appropriate scientific response is always: “Let’s test this.” :_H ● Question 13 Question: For many decades, scientists thought they understood how ozone breaks down in the stratosphere, creating ozone holes. However, new data show significantly lower reaction rates than can be explained by the long-held model.

What is the appropriate scientific approach for dealing with this contradiction?

Answer: ⬛ ✓ Conduct additional experiments to confirm the new data Topic: Nature of Science – Handling Contradictory Evidence (Section 1.2) Explanation: In science, when new data contradict existing theories or models, the correct response is to verify the data through further experimentation. Only replicable, confirmed evidence can justify revising or refining a theory.

i:!ćf

Scientific Method at Work:

From the “Taught by Chat GPT Sec 1” and “Sec 1 Note-Taking Guide”, this aligns with a key scientific value: Science is self-correcting, evidence-driven, and relies on replication.

If the new reaction rates conflict with the established ozone-depletion model, scientists must: •

Confirm the accuracy of the new data through repeated, well-designed experiments

•

Review experimental methods

•

Evaluate sources of error

•

Determine if the theory must be revised

This process is critical thinking in action, not blind acceptance or rejection.

+ Why the Other Options Are Incorrect: Option

Why It’s Wrong

+ Ignore the new data because it contradicts the accepted model

Anti-scientific. Ignoring data because it’s inconvenient halts progress.

+ Ask the public to vote on which data are correct

Science is not democratic—it’s based on evidence, not opinion

+ Accept whichever data the most famous scientists support

Science relies on peer-reviewed evidence, not authority or reputation

● Real-World Scientific Examples: This mirrors how the ozone depletion theory evolved: •

In the 1970s–80s, scientists like Rowland and Molina proposed that CFCs break down ozone.

•

Their model was accepted, but refinements occurred as satellite data and reaction rates were measured more precisely.

•

New findings led to adjustments in the model and stronger international environmental policy (e.g., the Montreal Protocol).

The process: Observation → Contradiction → Verification → Theory Adjustment

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ Conduct additional experiments to confirm the new data

Why?

Verification is the only way to determine if the new data are valid and if the model needs to be updated

Scientific Method Step

Repeating experiments and peer review

Core Scientific Value

Data over opinion, replication, and self-correction

Outcome

May lead to revision or refinement of the theory — if evidence supports it

ç' C

Final Takeaway:

Science doesn’t fear being wrong — it fears being untested.

When new evidence arises, the first scientific response is: "Let’s test it again." + Question 14 • ·Question: For almost 1500 years most scientists in Europe accepted Ptolemy’s geocentric planetary model that suggested the sun revolved around Earth. By the eighteenth century, most scientists supported a heliocentric model that suggests that Earth revolves around the sun.

What is an appropriate scientific basis for this change in view?

Answer: ⬛ ✓ The existing theory was changed to account for new data Topic: Nature of Science – Revising Theories Based on Evidence (Section 1.2) Explanation: This historical shift illustrates one of the core principles of science: when new evidence becomes available, scientists must be willing to revise or replace existing models. The transition from the geocentric (Earth-centered) to the heliocentric (Suncentered) model happened because observations increasingly supported the latter.

ˇ`†

Historical Background: •

•

•

•

Ptolemy’s geocentric model (2nd century CE): o

Earth at the center of the universe

o

Planets and the sun moved in complex circular paths (epicycles) around Earth

o

Widely accepted for 1,500+ years

Copernicus (1543) proposed the heliocentric model: o

Sun at the center

o

Earth and planets revolve around the sun

o

Initially controversial, but more consistent with observed planetary motion

Galileo’s telescope (early 1600s): o

Observed Jupiter’s moons, phases of Venus, and sunspots

o

These directly contradicted the geocentric model

Kepler’s Laws and Newton’s Law of Gravity gave strong mathematical support to heliocentrism

⬛ Conclusion: The heliocentric model replaced the old one because it explained the ✓ data better and more simply.

+ Why the Other Choices Are Incorrect: Option

Why It’s Wrong

+ The most prominent scientist that supported the geocentric model died

Science doesn’t change based on someone’s death—it changes based on evidence

+ The old theory was voted down by a scientific council

Scientific truth is not determined by voting; it's determined by data and reasoning

Option

Why It’s Wrong

Fame doesn’t determine accuracy—evidence does.

Galileo and Copernicus were controversial, not popular, supported by a popular scientist when they proposed heliocentrism! + The heliocentric model was

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer ⬛ ✓ The existing theory was changed to account for new data Why?

Observations and experiments (telescope data, planetary motion) contradicted geocentrism and supported heliocentrism

Scientific Principle

Theories must change when evidence contradicts them

Real Example

Galileo’s observations of Jupiter’s moons proved not all celestial bodies revolve around Earth

Main Idea

Science progresses by updating models to better match reality

ç' C

Final Thought:

Science is not static. When new tools, data, or perspectives arise, even centuries-old models can—and should—be challenged.

The heliocentric revolution is a powerful example of how science corrects itself over time. .ጥ ) Question 15 " Question: A woman does pushups by lowering her body to the ffoor using her arms and then pressing against the ffoor with her hands to push herself back up. Which force causes her to rise?

Answer: ⬛ ✓ The upward force that the ground exerts on the woman Topic: Newton’s Third Law of Motion (Physics – Section 1.3) Explanation: According to Newton's third law of motion, for every action, there is an equal and opposite reaction. When the woman pushes downward on the floor, the floor pushes upward on her with an equal force. It is this upward reaction force that lifts her body during a push-up.

]L From “Taught by Chat GPT Sec 1” and “Note-Taking Guide”: □ Y

Newton’s Third Law:

Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first.

•

Action: Woman’s arms push down on the floor

•

Reaction: Floor pushes back up on the woman

This reaction force is what actually lifts her body off the ground.

ç'C Understanding the Options: Answer Choice

Why It’s Right or Wrong

+ The downward force of gravity that Earth exerts on the woman

This pulls her down, not up—it opposes her motion

+ The downward force that the woman’s arms exert on the ground

This is the action force, but it doesn't cause her to rise directly

Answer Choice

Why It’s Right or Wrong

✓ The upward force that the ground exerts ⬛ on the woman

✓ This is the reaction force that pushes P her body up

+ The upward force that the woman’s arms exert on the ground

This isn't possible — her arms push down, not up

"^

Real-World Example of Newton’s Third Law: •

Walking: You push backward on the ground, the ground pushes you forward

•

Jumping: You push down with your legs, the ground pushes you up

•

Push-ups: You push down on the floor, the floor pushes you up

In all cases, motion is caused by the reaction force of the surface you're in contact with.

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ The upward force that the ground exerts on the woman

Why?

It’s the reaction force that causes her to rise, based on Newton’s Third Law

Scientific Principle

Every force has an equal and opposite reaction

Common Misconception

People think their own force "lifts" them — but it’s actually the reaction force from the ground

Related Discipline

Physics — Forces and Motion (Section 1.3)

C Final Thought: ç ' When you move, you’re always interacting with something else — and it’s usually that thing pushing you (not just you pushing it).

That’s Newton’s 3rd Law in action!

_Question 16 ` ‘ Question: Two boxes sitting on the ffoor look identical, but one has more mass than the other. What happens when the same net force, sufficient to overcome static friction, is applied to each box?

Answer: ⬛ ✓ The box with less mass accelerates more.

Topic: Newton’s Second Law of Motion (Physics – Section 1.3) Explanation: According to Newton’s Second Law, the acceleration of an object depends on the net force applied and its mass. If the same force is applied to two objects, the one with less mass will experience greater acceleration.

]L From “Taught by Chat GPT Sec 1” and “Note-Taking Guide”: □ Y

Newton’s Second Law of Motion:

F = ma ] Where: •

FFF = net force (in newtons, N)

•

mmm = mass (in kilograms, kg)

•

aaa = acceleration (in meters per second squared, m/s²)

Rewriting: a = \frac{F}{m} ] So, if the same force (F) is applied to both boxes: •

The box with less mass (m) will have a larger acceleration (a)

•

The box with more mass will accelerate less

ç'C Why the Correct Answer Makes Sense:

Box

Mass

Force Resulting Acceleration

Lighter Box Smaller Same ⬛ ✓ Greater acceleration Heavier Box Larger Same + Less acceleration This is one of the core principles of force and motion.

+ Why the Other Options Are Incorrect: Answer Choice

Why It’s Incorrect

+ The box with more mass accelerates more

This contradicts Newton’s second law — greater mass results in less acceleration for the same force

+ Both boxes accelerate at the same rate

That would only happen if they had equal mass

+ Both boxes remain at rest

The question says the force is enough to overcome static friction, so they will start moving

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer ⬛ ✓ The box with less mass accelerates more Why?

From Newton’s second law: a=F/ma = F/ma=F/m → for the same force, lower mass = higher acceleration

Key Concept

Acceleration is inversely proportional to mass when force is constant

Real-World Example

Pushing an empty shopping cart vs. a full one with the same effort

ç Final Tip: ' C

Think of Newton’s Second Law as: More mass, more resistance to change in motion.

That’s why lighter objects respond faster to the same push. ¸IE–

Question 17

Question: Two identical train engines are parked on parallel tracks. One engine has ten cars attached, and the other has no cars attached. Each engine exerts the same net force, which allows the train to overcome static friction. Which engine will be able to accelerate more?

Answer: ⬛ ✓ The engine not pulling any cars will accelerate more.

Topic: Forces and Motion – Newton’s Second Law (Section 1.3) Explanation: According to Newton’s Second Law of Motion (F=maF = maF=ma), if both engines exert the same force, the one with less total mass (i.e., no train cars attached) will experience a greater acceleration. More mass = more inertia = slower acceleration.

]L From “Taught by Chat GPT Sec 1” and “Sec 1 Note-Taking Guide”: □ Y

Newton’s Second Law:

a=Fma = \frac{F}{m}a=mF Where: •

aaa = acceleration

•

FFF = net force

•

mmm = mass

In this case: •

Engine A: pulling 0 cars → less mass → more acceleration

•

Engine B: pulling 10 cars → more mass → less acceleration Even though both engines exert the same net force, the difference in mass means they won’t accelerate equally.

+ Why the Other Answers Are Incorrect:

Answer Choice

Why It’s Wrong

+ The engine pulling ten cars will accelerate more

More mass = more resistance = slower acceleration for same force

+ Both engines will accelerate Only true if both had the same mass, which they don’t at the same rate + Both engines will remain at rest

†;'ü

The question says the force is enough to overcome static friction, so both engines will move

Real-World Connection:

If you try to push: •

A small rolling suitcase — it accelerates easily

•

A heavy cargo cart — it moves more slowly, even if you push just as hard

This is exactly what’s happening in the question.

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ The engine not pulling any cars will accelerate more ✓

Why?

Same force, less mass → greater acceleration

Scientific Principle

Newton’s Second Law: a=F/ma = F/ma=F/m

Key Idea

Acceleration is inversely proportional to mass

Related Concept

Inertia – the more mass an object has, the more it resists acceleration

ç' C

Final Insight:

Less mass, more motion — for the same force.

This is a perfect Newton’s Second Law scenario. ) Question 18 ' f ☁ | v ф * Question: A woman applies an upward force to a basket filled with groceries. Assume she is standing still. What will happen to the basket if the force she applies is greater than the force of gravity?

Answer: ✓ ⬛ The basket will move up.

Topic: Forces and Motion – Net Force & Gravity (Section 1.3) Explanation: When the upward force exceeds the downward force of gravity, there is a net upward force. This causes the basket to accelerate upward according to Newton’s Second Law: Fnet=Fapplied−Fgravity>0⇒Upward motionF_{\text{net}} = F_{\text{applied}} F_{\text{gravity}} > 0 \Rightarrow \text{Upward motion}Fnet=Fapplied−Fgravity >0⇒Upward motion

] From “Taught by Chat GPT Sec 1” and “Note-Taking Guide”: L□ ^" Key Physics Concepts: •

Gravity always pulls objects downward

•

To lift something, you must apply a force that is greater than gravity

•

If: o

Applied force = gravitational force → object remains stationary

o

Applied force > gravitational force → object accelerates upward

o

Applied force < gravitational force → object falls

ç'C Why the Correct Answer Makes Sense: Forces Acting

Outcome

Gravity pulls down

Constant downward force on the basket

Forces Acting

Outcome

Woman pushes up harder than gravity

Creates a net upward force, causing the basket to move up

+ Why the Other Choices Are Incorrect: Answer Choice

Why It’s Wrong

+ The basket will move sideways

No horizontal force is applied — motion is vertical only

+ The basket will remain at the same height

That only happens if upward force = gravity

+ The basket will move down

That only happens if gravity > applied force

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer ⬛ ✓ The basket will move up Why?

Because the applied force is greater than gravity, creating upward acceleration

Physics Principle

Net force determines motion: Fnet=maF_{\text{net}} = maFnet=ma

Key Idea

Direction of motion = direction of net force

Related Force

Gravitational force (weight) = mass × 9.8 m/s²

C Final Insight: ' ç Motion always follows the net force. If the total force points up, the object moves up.

This is basic but fundamental physics! i_ .f Л̄ ._. Question 1G z

Question: A heavy truck and a light car travel at the same velocity side-by-side on the highway. Both drivers apply the same braking force at the same moment.

What will happen to the two vehicles?

Answer: ⬛ ✓ The car will slow down more quickly than the truck.

Topic: Forces and Motion – Newton’s Second Law, Mass & Acceleration (Section 1.3) Explanation: Newton’s Second Law tells us: a=Fma = \frac{F}{m}a=mF If both the force (F) is the same, but the mass (m) is different, then the vehicle with less mass (the car) will experience greater acceleration (or in this case, deceleration).

]L From “Taught by Chat GPT Sec 1” and “Note-Taking Guide”: □ " Newton’s Second Law: ^ •

The same braking force is applied to both vehicles.

•

The truck has more mass → greater inertia → slower deceleration

•

The car has less mass → less resistance → slows down more quickly

This means the car will lose speed faster than the truck under the same braking force.

⬛ Example Calculation: Vehicle Mass Same Braking Force Applied Resulting Deceleration Car

Lower Same

⬛ Greater deceleration ✓

Truck Higher Same

+ Smaller deceleration

+ Why the Other Options Are Incorrect:

Answer Choice

Why It’s Wrong

+ The truck will slow down more quickly than the car

Heavier objects decelerate less when same force is applied

+ Both vehicles will slow down at the same rate

That only happens if the force-to-mass ratio is equal, which it’s not here

+ The car will slow down but the truck will continue at the same speed

The truck is also braking—it just slows more gradually

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer ⬛ ✓ The car will slow down more quickly than the truck Why?

Same force, less mass = greater deceleration (Newton’s Second Law)

Key Concept

Mass resists changes in motion (inertia), so more mass = slower acceleration/deceleration

Real-Life Example

A fully loaded semi takes longer to stop than a small sedan, even with strong brakes

'çC

Final Insight:

Same force, less mass → greater change in motion.

In braking, that means the lighter object slows down faster.

Question 20 Question: Which force causes graphite from the tip of a pencil to transfer to the paper? ✓ Correct Answer: Friction ⬛

□ Topic: ]L

Physics – Contact Forces: Friction (Section 1.3: Forces and Motion)

C What is this question testing? ç ' This question tests your understanding of friction as a force that resists motion and causes surface materials to interact. It's asking you to identify which force is responsible for transferring matter (graphite) from one surface (pencil tip) to another (paper).

✓ Why this answer is correct: ⬛ Friction is the resisting force between two surfaces in contact. When you press a pencil against paper and move it, friction acts between the graphite and the paper fibers, scraping off tiny particles of graphite and depositing them onto the paper.

Without friction, the graphite wouldn't stick or transfer, and you'd see no writing. The pencil marks are literally left-behind layers of graphite pulled from the tip by frictional interaction with the rough paper surface.

⬛ Visual Concept (Not a formula-heavy topic): “ Imagine sliding a crayon across a smooth glass vs. rough paper: •

On glass: low friction → little transfers

•

On paper: high friction → more pigment (or graphite) transfer

+ Why the other options are incorrect: Incorrect Choice

Why It’s Incorrect

Gravity

+ Gravity pulls objects down, but it doesn’t scrape material off a pencil

Air Resistance

+ Air resistance is a drag force in the air; it doesn't act between solid surfaces in contact

Incorrect Choice

Why It’s Incorrect

Tension

+ Tension is a pulling force along a rope or string—not involved in pencil-paper contact

'Cç Real-World Examples: •

When you rub two surfaces together, heat or particles may be produced—this is due to friction.

•

Erasers also use friction: the rubber grips and removes graphite particles by frictional contact.

⬛ Summary Breakdown: ✓ Component

Explanation

Correct Answer

⬛ ✓ Friction

What It Does

Allows graphite to be scraped off the pencil tip and deposited on paper

Concept

Friction = contact force that causes material transfer between surfaces

Why Others Are Wrong

They don’t involve surface interactions needed for writing

S Question 21 ’ F Question: Which force keeps Jupiter in orbit around the Sun? ✓ Correct Answer: Gravity ⬛

□ Topic: ]L

Physics – Gravitational Forces s Orbital Motion (Section 1.3: Forces in Nature) Specifically covers Newton’s Law of Universal Gravitation and orbital dynamics

ç 'C

What is this question testing?

This question is testing your understanding of what force governs the motion of planets, moons, and other celestial bodies. It's specifically asking you to identify the central force responsible for planetary orbits in space.

✓ Why this answer is correct: ⬛ According to Newton’s Law of Universal Gravitation, every object with mass exerts a gravitational pull on every other object with mass. The Sun, having an enormous mass, pulls Jupiter toward it via gravity.

•

Jupiter doesn’t crash into the Sun because of its inertia (forward motion).

•

The result is a curved path—orbit—due to the balance between inertia and gravity.

This gravitational force acts as the centripetal force that continuously changes the direction of Jupiter’s velocity, keeping it in a stable orbit.

v ٨

Gravitational Force Equation:

F=Gm1m2r2F = G \frac{m_1 m_2}{r^2}F=Gr2m1m2 Where: •

FFF is the gravitational force

•

GGG is the gravitational constant

•

m1m_1m1 and m2m_2m2 are the two masses

•

rrr is the distance between their centers

+ Why the other options are incorrect:

Incorrect Choice

Why It’s Wrong

Air resistance + There is no air in space; air resistance requires an atmosphere Kinetic friction

+ Friction is a contact force; space is a vacuum, and no surfaces are rubbing together

Magnetism

+ The Sun’s magnetic field affects some solar phenomena, but it’s not responsible for planetary orbits—that’s gravity's job

C Real-World Examples: ç ' •

The Moon stays in orbit around Earth for the same reason: Earth’s gravitational pull.

•

Satellites orbit Earth because gravity keeps pulling them down, while their forward velocity keeps them from crashing.

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ Gravity

Key Principle

Newton’s Law of Universal Gravitation

Main Idea

Gravity provides the centripetal force needed to keep planets in orbit

Misconception Fixed

No friction or magnetism in space controls orbits—only gravity does

™ Question 22 ' “ ~ : Question: Which force causes a jet airplane to stop on a runway? ⬛ Correct Answer: Friction ✓

]L Topic: □ Physics – Friction s Contact Forces (Section 1.3: Types of Forces and Motion)

'çC What is this question testing?

This question is assessing your understanding of which forces oppose motion and are responsible for bringing moving objects to a stop. Specifically, it relates to how friction acts as a resistive force between moving objects and surfaces.

✓ Why this answer is correct: ⬛ When a jet lands, friction between the airplane’s wheels and the runway helps slow it down. This frictional force acts opposite to the direction of the jet’s motion and converts kinetic energy into thermal energy.

•

In addition to braking systems, friction from the tires on the ground is essential to bring the jet to a complete stop.

•

Air resistance also plays a minor role, but the primary force acting once the plane touches down is friction with the runway surface.

⬛ Related Concept: “ Friction is a contact force that resists motion between two surfaces. It is crucial for stopping cars, airplanes, or any other object with rolling or sliding parts.

+ Why the other options are incorrect: Incorrect Choice

Why It’s Incorrect

Gravity

+ Gravity pulls the airplane downward, but it doesn't slow horizontal motion. It keeps the plane on the ground but does not resist forward movement.

Incorrect Choice

Why It’s Incorrect

Tension

+ Tension is a pulling force along strings, ropes, or cables. It's not involved in stopping a jet.

Centripetal force

+ Centripetal force causes circular motion (e.g., turning). A plane stopping in a straight line isn’t making a circular motion, so centripetal force is irrelevant.

çC Real-World Examples of Friction at Work: ' •

Car tires slowing down on a road.

•

Brake pads applying friction to stop wheels.

•

Athletes sliding on turf and stopping because of friction between their shoes and the ground.

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ Friction

Main Idea

Friction opposes motion and helps objects come to a stop on contact surfaces

Physics Concept

Contact force that resists movement between surfaces

Why Others Are Wrong

Other options either act in different directions (gravity) or don't apply (tension, centripetal)

C ( ı Question 23 ; Question: Which force causes meteors to burn up when they enter Earth’s atmosphere? ✓ Correct Answer: Friction ⬛

]L Topic: □ Physics – Friction and Atmospheric Entry (Section 1.3: Types of Forces) This falls under contact forces and energy transfer during motion through fluids.

C What is this question testing? ç ' This question tests your understanding of how friction between objects and the atmosphere generates heat and can cause physical changes (like burning). It explores what happens during high-speed atmospheric entry.

✓ Why this answer is correct: ⬛ As a meteor enters Earth’s atmosphere, it’s moving at incredibly high speeds (often over 25,000 mph). The air molecules in the atmosphere resist its motion.

This resistance is friction, and it creates intense heat due to energy transfer: •

Kinetic energy (from speed) → thermal energy (heat).

•

The heat can be so intense that the meteor begins to glow and burn up, which is what we see as a “shooting star.”

f˛ Related Concept: µ •

Friction in fluids (like air) is often called air resistance or drag.

•

Friction converts motion energy into heat, which is why meteors burn during entry.

+ Why the other choices are incorrect: Incorrect Choice Gravity

Why It’s Incorrect + Gravity pulls the meteor toward Earth but does not create heat. It’s the friction with the atmosphere that causes it to burn.

Incorrect Choice

Why It’s Incorrect

Magnetism

+ Earth’s magnetic field affects charged particles, not solid meteors. It plays no role in the meteor burning.

Tension

+ Tension is a pulling force within strings, cables, or muscles—not relevant to atmospheric motion.

'çC

Real-World Examples: •

Spacecraft re-entry: Engineers use heat shields to withstand friction-generated heat when re-entering Earth's atmosphere.

•

Meteor showers: These are caused by friction from tiny bits of rock hitting the atmosphere.

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ Friction

Key Principle

Friction with air causes thermal energy buildup

Effect

The meteor burns as it moves through dense atmospheric layers

Misconception Fixed Gravity brings meteors to Earth, but friction causes the burn-up Question 24 Question: A slingshot is a Y-shaped stick with rubber bands between the prongs for shooting stones and other small projectiles. A stone is shot by first placing it in the slingshot holder, which is attached to the rubber bands. The stone and holder are then pulled back, stretching the rubber bands. When released, the stone is propelled forward and leaves the slingshot at a high speed.

Which type of energy transformation occurs from the point when the rubber bands are fully stretched to when the stone leaves the slingshot?

⬛ Correct Answer: Elastic potential energy is converted into kinetic energy ✓

□ Topic: ] L Energy Transformations – Potential and Kinetic Energy (Section 1.4: Energy s Forces) This is about recognizing energy types and understanding how energy transforms from stored (potential) to motion (kinetic).

ç What is this question testing? ' C The question evaluates your knowledge of: •

Different forms of mechanical energy.

•

How energy is stored (in this case, elastic energy in stretched rubber bands).

•

How that stored energy is then converted into motion (kinetic energy).

✓ Why this answer is correct: ⬛ •

When you pull back on the rubber bands of a slingshot, the bands store energy. This stored energy is called elastic potential energy.

•

When the bands are released, that energy is quickly transformed into kinetic energy, which propels the stone forward.

This transformation: Elastic Potential Energy → Kinetic Energy This process follows the law of conservation of energy: energy is not lost; it simply changes form.

+ Why the other choices are incorrect:

Incorrect Choice

Why It’s Incorrect

Chemical potential energy is converted into gravitational potential energy

+ No chemical reactions are happening here. There is no chemical energy involved in stretching or releasing a slingshot.

Gravitational potential energy is converted into thermal energy

+ This transformation describes an object falling and generating heat, not a slingshot being used to launch a projectile.

Elastic potential energy is converted into gravitational potential energy

+ The stone is not just being lifted; it's being launched horizontally. The energy is becoming motion, not just height-based potential.

Ç Related Concepts: ¸• ?

" ^

•

Elastic Potential Energy: Stored in stretched or compressed materials like rubber bands, springs, or bows.

•

Kinetic Energy: Energy of motion. The faster the object moves, the more kinetic energy it has.

Real-Life Examples: •

Archery: A bow stores elastic energy when drawn; it turns into kinetic energy when released.

•

Trampolines: When compressed, they store energy that bounces a person upward.

•

Mousetraps: Store energy in a spring that quickly releases kinetic energy when triggered.

⬛ Summary Breakdown: ✓ Component

Explanation

Correct Answer

✓ Elastic potential energy is converted into kinetic energy ⬛

Component

Explanation

Main Concept

Energy transformation from stored energy in rubber bands to motion

Why It’s Right

Pulling the slingshot stores energy; releasing it turns it into motion energy

Why Others Are Wrong

Other options mention unrelated forms of energy like chemical or gravitational

¡

Question 25

Question: Which type of energy conversion occurs at the moment fireworks explode? ⬛ Correct Answer: Chemical potential energy is converted into kinetic energy ✓

□ Topic: ] L Energy Transformations – Chemical to Kinetic (Section 1.4: Energy and Forces) Covers how stored energy in chemical compounds gets released and turned into motion and sound.

'çC What is this question testing?

This question tests your understanding of how energy stored in chemical bonds (in this case, inside fireworks) is released and converted into motion, especially when a rapid reaction (like an explosion) occurs.

✓ Why this answer is correct: ⬛ Fireworks contain chemical compounds (like gunpowder) that store chemical potential energy. When ignited, a chemical reaction (combustion) occurs rapidly, releasing a large amount of kinetic energy (motion of fragments, gases) and thermal energy.

At the exact moment of explosion, the most immediate conversion is: Chemical Potential Energy → Kinetic Energy

•

This kinetic energy causes the explosive motion outward of particles and colored fragments.

•

Additional forms like thermal energy (heat) and light are also released, but the question specifically asks about the moment fireworks explode, emphasizing motion.

+ Why the other choices are incorrect: Incorrect Choice

Why It’s Incorrect

Elastic potential energy is converted into thermal energy

+ No elastic (spring-like) material is involved. This is not how fireworks function.

Gravitational potential energy is converted into thermal energy

+ Fireworks are exploding due to a chemical reaction, not due to falling or height.

Elastic potential energy is converted into gravitational potential energy

+ Again, this has nothing to do with stretching/compressing materials or height change.

•¸?Ç

Related Concepts: •

Chemical potential energy is energy stored in bonds between atoms.

•

When fireworks combust, the bonds break and release energy as motion, heat, sound, and light.

•

The initial conversion is primarily to kinetic energy, which propels fragments outward.

Y· Real-Life Examples: •

Fireworks, car engines, rockets all convert chemical energy into kinetic energy.

•

Firecrackers and bullet cartridges work the same way: chemical energy becomes explosive motion.

✓ Summary Breakdown: ⬛

Component

Explanation

Correct Answer

⬛ ✓ Chemical potential energy is converted into kinetic energy

Key Principle

Energy stored in chemical bonds is released as motion in an explosion

Misconception Fixed

Elastic or gravitational energy isn’t involved in fireworks—they’re powered by chemical reactions

`‘_

Question 26

Question: What energy conversion takes place as a box slides to a stop on a horizontal table? ⬛ ✓ Correct Answer: Kinetic energy is converted into thermal energy

] Topic: □ L Energy Transformations – Friction s Heat (Section 1.4: Energy and Forces) This focuses on how mechanical energy transforms, especially due to frictional forces during motion.

C What is this question testing? ç ' This question tests whether you understand: •

What happens to an object’s energy as it slows down.

•

That friction is the force that resists motion and transforms energy into heat.

•

The principle of conservation of energy—energy isn’t lost, but converted.

✓ Why this answer is correct: ⬛ When a moving box slides on a table, it slows down due to friction between the box and the surface. The kinetic energy (energy of motion) the box had is not destroyed—it is transformed into thermal energy (heat), which warms up both the box and the table.

Transformation:

Kinetic Energy → Thermal Energy This is a textbook case of energy dissipation via friction.

+ Why the other options are incorrect: Incorrect Choice

Why It’s Incorrect

Gravitational potential energy is converted into kinetic energy

+ This would happen if the box were falling, not sliding on a flat surface.

Chemical potential energy is + No chemical or elevation changes are converted into gravitational potential happening—this isn't a chemical reaction or a energy height-related shift.

Elastic potential energy is converted into gravitational potential energy

¸•?Ç

"^

+ Nothing is being stretched or compressed, and no height change is involved.

Related Concepts: •

Friction resists motion and generates heat.

•

Kinetic energy (from motion) becomes thermal energy through friction.

Real-Life Examples: •

Car brakes: Kinetic energy becomes heat as friction slows the car.

•

Sliding on a wood floor: Your socks heat up slightly from friction.

•

Skidding objects: Slow down due to energy lost as heat.

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

✓ Kinetic energy is converted into thermal energy ⬛

Component

Explanation

Main Concept

Friction causes energy from motion to become heat

Why It’s Right

As the box slows, its motion energy becomes heat energy

Common Misconception Fixed

Energy doesn’t disappear—it just changes form through processes like friction

i_.f

Question 27

Question: What energy conversion occurs in a car's engine? ⬛ Correct Answer: Chemical potential energy is converted into thermal energy ✓

] Topic: L □ Energy Transformations – Chemical and Thermal Energy (Section 1.4: Energy and Forces)

C What is this question testing? ç ' This question evaluates your understanding of how fuel-based engines work, and how energy stored in fuel is released and transformed during combustion.

✓ Why this answer is correct: ⬛ In a car engine, gasoline contains chemical potential energy—energy stored in the bonds of molecules. When the fuel combusts (burns) inside the engine’s cylinders, a chemical reaction takes place. This chemical energy is: 1. Released as thermal energy (heat), which increases the pressure in the cylinder.

2. This heat and pressure cause mechanical movement, but thermal energy is the immediate product of the chemical reaction.

So, the first step in the transformation process is

Chemical Potential Energy → Thermal Energy

⬛ Additional Step (Beyond Scope of Question): “ Later in the engine process, that thermal energy becomes kinetic energy (motion), which drives the car. But this question focuses on the energy conversion that occurs in the engine itself—not the wheels or car movement.

+ Why the other choices are incorrect: Incorrect Choice

Why It’s Incorrect

Kinetic energy is converted into elastic potential energy

+ That would occur if something moving were storing energy in a spring or elastic—not relevant here

Gravitational potential energy is converted into electrical potential energy

+ Car engines don't operate via gravity or produce electrical potential energy this way

Thermal energy is converted into gravitational potential energy

+ No change in height or position against gravity is involved—this is unrelated

Ç ¸ Related Concepts: • ?

"^

•

Chemical energy is stored in gasoline.

•

Combustion transforms that energy into heat.

•

That heat causes gas to expand and push pistons, eventually powering the car.

Real-Life Example: •

Gasoline engines: Fuel is ignited, and the heat from the explosion pushes the pistons.

•

Jet engines: Use chemical energy from fuel to create thermal energy and thrust.

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

✓ Chemical potential energy is converted into thermal ⬛ energy

Main Concept Why It’s Right Common Misconception Fixed

Engines use combustion to convert fuel’s stored energy into heat Combustion = chemical reaction → produces heat (thermal energy) The first transformation is to thermal—not directly to motion or electrical

¡ Question 28 : . “ ’ Question: Which kind of electromagnetic radiation carries information to and from a cell phone when it is used for a phone call? ⬛ Correct Answer: Microwaves ✓

] Topic: L □ Electromagnetic Spectrum – Communications Technology (Section 3.3: Electromagnetic Waves and Their Uses)

C What is this question testing? ' ç This question is testing your understanding of which type of electromagnetic (EM) wave is used in modern wireless communications, specifically in cell phones.

You need to: •

Identify the range of electromagnetic waves used in cell phone technology.

•

Distinguish between different wave types based on wavelength and frequency.

✓ Why this answer is correct: ⬛ Cell phones use microwaves (a subset of the radio wave region) to send and receive data during a call. These waves: •

Have frequencies high enough to carry lots of information.

•

Have wavelengths short enough to be transmitted by small antennas.

•

Are non-ionizing and safe for communication purposes.

Microwaves are used for: •

Cellular communication

•

Wi-Fi signals

•

GPS

•

Bluetooth

They’re efficient for transmitting signals over long distances with minimal interference.

+ Why the other choices are incorrect: Incorrect Option Why It’s Incorrect X-rays

+ X-rays are high-energy and ionizing—dangerous and not used for communications.

Infrared radiation

+ Infrared is used for short-range communication (e.g., TV remotes), not cell phones.

Ultraviolet radiation

+ Ultraviolet rays are ionizing and more suited for sterilization—not data transfer.

¡]# Electromagnetic Spectrum Overview:

Wave Type

Wavelength

Radio Waves Longest

Uses AM/FM, TV, walkie-talkies

Microwaves Shorter than radio ¯_. ⬛ Cell phones, Wi-Fi, radar, GPS I Infrared

Even shorter

TV remotes, thermal cameras

Visible Light Middle of spectrum Human vision Ultraviolet

Shorter than visible Sterilization, tanning beds

X-rays

Very short

Gamma Rays Shortest

Medical imaging Cancer treatment, nuclear reactions

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ Microwaves

Main Idea

Microwaves are used in cell phones to carry voice/data over long distances

Why It’s Right

They are efficient, non-ionizing, and fall in the right part of the EM spectrum for this purpose

Misconception Fixed

Not all EM waves carry information—only certain ones like radio and microwaves do

I±' Question 2G Question: A cashier who has been handed a hundred-dollar bill may check its authenticity by holding it under a special lamp that emits electromagnetic radiation mostly at wavelengths slightly shorter than visible light. The electromagnetic radiation makes a pattern of previously invisible markings on the bill glow brightly, or ffuoresce.

Which kind of electromagnetic radiation does the lamp emit to produce this effect? ✓ Correct Answer: Ultraviolet radiation ⬛

]L Topic: □ Electromagnetic Spectrum – Applications of Light (Section 3.3: Electromagnetic Waves and Their Uses)

ç What is this question testing? ' C This question is testing your knowledge of the electromagnetic spectrum, especially how different types of waves are used in real-world applications like detecting counterfeit money. You’re being asked to associate a phenomenon (fluorescence) with a specific type of radiation.

✓ Why this answer is correct: ⬛ Ultraviolet (UV) light has a shorter wavelength than visible light and is often used in devices that cause certain materials to fluoresce, or glow.

When UV light shines on special inks or materials (like those used in money or ID cards), they absorb the UV energy and re-emit it as visible light, making hidden patterns or features visible.

So: Ultraviolet radiation → causes fluorescence → reveals markings on the bill

+ Why the other choices are incorrect: Incorrect Option

Why It’s Incorrect

Microwaves

+ Used in communication and cooking—not energetic enough to cause fluorescence.

Infrared radiation

+ Used for heat sensing and night vision—does not cause fluorescence.

Incorrect Option

Why It’s Incorrect

X-rays

+ Too energetic and dangerous; used for imaging bones—not practical or safe for bills.

]¡EM Spectrum Positioning (for context): # Wave Type Relative Wavelength Common Uses Radio Waves Longest

AM/FM, phones, TV signals

Microwaves Shorter than radio

Phones, radar, microwave ovens

Infrared

Below visible

Heat sensing, remotes

Visible Light ROYGBIV

Human vision

Ultraviolet Shorter than visible

Fluorescent ink, sterilization, tanning

X-rays

Medical imaging

Much shorter

Gamma Rays Shortest

¸?• Ç

Nuclear/space phenomena, cancer therapy

Real-World Examples Using UV Light: •

Banknote and ID verification

•

Black light posters and invisible ink

•

Detecting bodily fluids in forensic science

•

Sterilization and sanitation

⬛ ✓ Summary Breakdown: Component

Explanation

Correct Answer

✓ Ultraviolet radiation ⬛

Component

Explanation

Topic

EM radiation types and their uses

Why It’s Right

UV radiation reveals hidden markings by causing fluorescence

Misconception Fixed

UV is just outside visible light and is commonly used in anticounterfeiting

n Question 30 ↓' Question: After natural disasters, first responders can locate survivors in the rubble by using thermal detectors. Because the victims’ bodies are warmer than their surroundings, the difference in temperature is detected by electromagnetic waves.

Which part of the electromagnetic spectrum is being detected? ✓ Correct Answer: Infrared radiation ⬛

□ Topic: ] L Electromagnetic Spectrum – Infrared Radiation and Heat Detection (Section 3.3: Electromagnetic Waves and Their Uses)

C What is this question testing? ç ' This question tests your understanding of: •

The types of electromagnetic radiation.

•

How different types are used in technology, especially in thermal imaging or heat detection.

•

How infrared radiation is tied to temperature differences.

✓ Why this answer is correct: ⬛ Infrared radiation is emitted by all warm objects. The warmer an object is, the more infrared radiation it emits.

Thermal detectors (like thermal cameras used by emergency responders):

•

Detect infrared radiation emitted by human bodies.

•

Convert that radiation into images showing temperature differences.

•

This allows rescuers to find warm bodies in otherwise cool rubble.

So the electromagnetic wave being detected is infrared.

+ Why the other choices are incorrect: Incorrect Option

Why It’s Incorrect

Radio waves

+ Used for broadcasting and communication—not for detecting heat.

Ultraviolet radiation

+ Used for sterilization and causing fluorescence—not tied to heat sensing.

X-rays

+ Used for imaging bones and internal structures—penetrates matter, not heat-sensitive.

: Visual: Where Infrared Falls on the EM Spectrum _H arduino Copy | Radio | Micro | **Infrared** | Visible | UV | X-ray | Gamma | |<------LOW ENERGY------>|

|<------HIGH ENERGY -------- >|

•

Infrared has longer wavelengths than visible light but shorter than microwaves.

•

It is invisible to the human eye but detectable by sensors tuned to heat.

"^ Real-Life Uses of Infrared Radiation: •

Thermal imaging in emergency response (e.g., search C rescue).

•

Night vision goggles.

•

Remote controls for electronics.

•

Weather satellites monitoring cloud temperatures.

⬛ ✓ Summary Breakdown: Component

Explanation

Correct Answer

⬛ Infrared radiation ✓

Main Concept

Warm bodies emit infrared energy, which thermal detectors use to find people

Why It’s Right

Infrared radiation directly relates to temperature differences—key in heat detection

Misconception Fixed

Not all EM waves sense heat—only infrared is used in thermal imaging systems

⬛ Question 31 Question: Airport security uses electromagnetic radiation to form images of objects inside passenger luggage.

Which type of electromagnetic radiation is used in this way? ✓ Correct Answer: X-rays ⬛

L Topic: □ ] Electromagnetic Spectrum – Penetrating Radiation in Imaging Technology (Section 3.3: Electromagnetic Waves and Their Uses)

ç'C What is this question testing?

This question assesses your ability to: •

Match types of electromagnetic radiation with their real-world applications, specifically imaging.

•

Understand which types of EM radiation can penetrate solid objects to reveal hidden structures.

✓ Why this answer is correct: ⬛ X- rays are high-frequency, high-energy electromagnetic waves that can: •

Penetrate most materials, especially soft or non-metallic ones.

•

Create contrast images based on the density of objects they pass through.

At airport security, X-ray scanners are used to: •

Examine the contents of luggage without opening it.

•

Detect prohibited items like weapons, liquids, or explosives.

+ Why the other choices are incorrect: Incorrect Option

Why It’s Incorrect

Radio waves

+ Used for communication and broadcasting—cannot form images of internal structures.

Visible light

+ Cannot penetrate luggage; only useful for surface-level visuals.

Ultraviolet radiation

+ Used to detect fluorescence—not suited for deep imaging through opaque materials.

¡]#

EM Spectrum Context:

Type

Penetration Ability

Used For

Radio waves No penetration

Phones, radios, broadcasting

Microwaves Low penetration

Wi-Fi, radar, cell communication

Infrared

Surface thermal imaging Night vision, heat sensors

Visible light Surface reflection only X-rays

Vision, photography

Penetrate soft materials ✓ ⬛ Medical scans, airport luggage screening

Type

Penetration Ability

Gamma rays Deep penetration, risky

¸?• Ç

Used For Cancer treatment, nuclear scans

Real-Life Application of X-rays in Airports: •

Conveyor belt scanners

•

Backscatter X-ray scanners for body scans (less common now)

•

X-ray diffraction machines for package scanning

X-ray energy is absorbed differently by dense (metal) and soft (plastic, fabric) items, creating an image of contrasts.

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ X-rays

Main Concept

X-rays are high-energy EM waves that penetrate materials for imaging

Why It’s Right

X-rays provide non-invasive views inside luggage, allowing detection of hidden items

Misconception Fixed

Not all EM waves form images—only those with high energy and short wavelength, like X-rays

J Corrected Question 32 Question: Which type of wave has a longitudinal motion? ✓ Correct Answer: Sound waves ⬛

□ Topic: ]L Wave Types – Transverse vs. Longitudinal Motion (Section 3.1: Waves and Energy)

'Cç What is this question testing?

This question tests your knowledge of: •

The two main types of mechanical waves: longitudinal and transverse.

•

How waves transfer energy through particle movement.

•

The nature of sound waves, including their motion through a medium.

✓ Why this answer is correct: ⬛ Sound waves are longitudinal waves, which means: •

The particles of the medium (like air, water, or solid materials) vibrate parallel to the direction the wave is moving.

•

The motion consists of compressions (particles pushed together) and rarefactions (particles pulled apart).

So, when a sound wave moves through air: •

Air molecules vibrate back and forth along the direction of wave travel, not up and down.

This defines longitudinal motion.

+ Why the other choices are incorrect: Incorrect Option

Why It’s Incorrect

Gamma waves

+ Gamma rays are electromagnetic waves, which move via transverse motion.

Transverse waves

+ This is a wave category, not a specific wave type; transverse motion ≠ longitudinal motion.

Light waves

+ Light waves are transverse electromagnetic waves, not longitudinal.

¸?•Ç

Key Differences Between Wave Types:

Wave Type

Motion Direction

Longitudinal Particles move parallel to wave travel

Examples Sound, seismic P-waves

Transverse Particles move perpendicular to wave travel Light, water surface waves

N Real-Life Examples of Sound Waves: I ( •

A tuning fork vibrating and sending compressions through air.

•

Human speech and music.

•

Ultrasound in medical imaging.

•

Echoes bouncing off walls or cliffs.

All of these involve air or another medium vibrating back-and-forth, not side-to-side.

⬛ ✓ Summary Breakdown: Component

Explanation

Correct Answer

⬛ ✓ Sound waves

Main Concept

Sound waves are longitudinal, with particles moving in the same direction as wave travel

Why It’s Right

Sound propagates by compressions and rarefactions, not by transverse vibration

Misconception Fixed

Not all waves are transverse—sound is a mechanical, longitudinal wave

:.“¡’

Corrected Question 33

Question: Which is a characteristic of electromagnetic waves? ✓ Correct Answer: Transverse wave motion ⬛

]L Topic: □ Properties of Electromagnetic Waves (Section 3.1: Waves and Energy)

' çC

What is this question testing?

This question assesses your understanding of: •

The motion characteristics of electromagnetic (EM) waves.

•

The difference between transverse and longitudinal wave behavior.

•

Basic wave mechanics as it applies to light and other EM waves.

✓ Why this answer is correct: ⬛ Electromagnetic waves (such as light, microwaves, radio waves, etc.) consist of electric and magnetic fields oscillating perpendicularly to each other and perpendicular to the direction of wave travel. This behavior is called transverse wave motion.

In transverse waves: •

The disturbance (field oscillation) is perpendicular to the direction of the wave's movement.

This is a fundamental property of all EM waves.

+ Why the other choices are incorrect: Incorrect Option

Why It’s Incorrect

Travels faster through water + EM waves travel faster in a vacuum and slower in water than air than in air.

Longitudinal wave motion Can travel only through a vacuum

+ EM waves are not longitudinal. Sound waves are longitudinal. + EM waves can travel through a vacuum (unlike sound), but also through matter.

¸?•Ç

Key Characteristics of Electromagnetic Waves:

Property

Explanation

Type of motion

Transverse (electric and magnetic fields perpendicular to wave direction)

Medium needed?

No. EM waves can travel through the vacuum of space

Speed

Fastest in vacuum (approximately 300,000 km/s or 186,000 miles/sec)

Examples

Radio, microwave, infrared, visible light, ultraviolet, X-rays, gamma rays

◆ · Fun Fact: u r Unlike sound, which requires a medium, EM waves can travel through empty space. This is why sunlight reaches Earth from 93 million miles away!

⬛ Summary Breakdown: ✓ Component

Explanation

Correct Answer

✓ Transverse wave motion ⬛

Main Concept

EM waves oscillate perpendicularly to the direction of wave motion

Why It’s Right

All EM waves behave as transverse waves, which distinguishes them from mechanical waves

Misconception Fixed

EM waves don’t require matter, aren’t longitudinal, and don’t travel fastest in water

⬛ Corrected Question 34 Question: Which subatomic particle is located outside the nucleus? ✓ Correct Answer: Electron ⬛

]L Topic: □ Atomic Structure – Location of Subatomic Particles (Section 2.2: Atomic Theory)

C What is this question testing? ç ' This question tests your knowledge of: •

The basic structure of the atom,

•

The location and characteristics of the three major subatomic particles: protons, neutrons, and electrons.

⬛ Why this answer is correct: ✓ An atom consists of: •

A nucleus, which contains protons (positive charge) and neutrons (no charge),

•

And electrons, which: o

Have a negative charge,

o

Are found in the electron cloud that surrounds the nucleus,

o

Move very rapidly and occupy most of the atom's volume.

Thus, electrons are the only subatomic particles that exist outside the nucleus.

+ Why the other choices are incorrect: Incorrect Option

Why It’s Incorrect

Proton

+ Located inside the nucleus; carries a positive charge.

Neutron

+ Also located inside the nucleus; no charge (neutral).

Ion

+ Not a subatomic particle—an ion is a whole atom or molecule with a net charge.

H_: Visual – Atom Diagram: Electron cloud (electrons) ⬌⬌⬌⬌⬌

| |

| Nucleus

|

| (protons C neutrons) | |

|

" Fun Fact: ^ The mass of electrons is negligible compared to protons and neutrons. Most of an atom's mass is concentrated in its tiny nucleus, even though most of its volume comes from the electron cloud.

⬛ Summary Breakdown: ✓ Component

Explanation

Correct Answer

⬛ ✓ Electron

Main Concept

Electrons are the only subatomic particles located outside the nucleus

Why It’s Right

Electrons orbit the nucleus in a cloud and are responsible for chemical behavior

Misconception Fixed

Protons and neutrons are in the nucleus; ions are atoms, not particles

⬛ Question 35

Question: What charge does a neutron have? ⬛ Correct Answer: No charge ✓

□ Topic: ] L Subatomic Particles – Charge and Location (Section 2.2: Atomic Theory)

C What is this question testing? ç ' This question checks your understanding of: •

The three main subatomic particles (proton, neutron, electron),

•

Their electric charges, and

•

Basic atomic structure knowledge.

✓ Why this answer is correct: ⬛ Neutrons are subatomic particles located in the nucleus of an atom and have: •

No electric charge, meaning they are electrically neutral.

•

Their main job is to add mass to the atom and help stabilize the nucleus (especially in atoms with many protons).

That's why the name is “neutron” — it comes from “neutral.”

+ Why the other choices are incorrect: Incorrect Option

Why It’s Incorrect

Positive charge

+ This is the charge of a proton, not a neutron.

Negative charge + Electrons carry a negative charge. Neutrons have none.

Incorrect Option

Why It’s Incorrect

Variable charge

+ Subatomic particles have fixed charges; neutrons are always neutral.

_H: Visual Summary of Subatomic Particles: Particle Location in Atom Charge

Relative Mass

Proton In nucleus

+1 (positive) 1 amu

Neutron In nucleus

0 (neutral) 1 amu

Electron Outside nucleus -1 (negative) ~0.0005 amu

"^

Important Applications of Neutrons: •

Neutrons are used in nuclear reactors to initiate chain reactions.

•

The number of neutrons determines the isotope of an element.

•

Too many or too few neutrons can cause an atom to be unstable (radioactive).

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ No charge

Main Concept

Neutrons are neutral particles found in the atomic nucleus

Why It’s Right

Neutrons are named for their lack of charge and help balance nuclear forces

Misconception Fixed

Protons are positive, electrons are negative, but neutrons are always neutral

● Corrected Question 36

Question: A chocolate chip cookie is made with dough and chocolate chips.

Which type of substance is a chocolate chip cookie? ✓ Correct Answer: Mixture ⬛

□ ] Topic: L Classification of Matter – Elements, Compounds, Mixtures (Section 2.3: Elements, Compounds, and Mixtures)

'çC What is this question testing?

This question tests your ability to: •

Classify matter based on its physical and chemical structure,

•

Recognize the difference between pure substances (elements, compounds) and mixtures.

✓ Why this answer is correct: ⬛ A chocolate chip cookie is a heterogeneous mixture, because: •

It contains different ingredients (e.g., dough and chocolate chips) that are not chemically bonded.

•

You can physically separate its parts.

•

The composition is not uniform throughout; some bites have more chips, others more dough.

A mixture: •

Can be homogeneous (uniform throughout, like salt water), or

•

Heterogeneous (like cookies or salad).

So, the correct classification is mixture.

+ Why the other choices are incorrect: Incorrect Option

Why It’s Incorrect

Element

+ An element is made of only one type of atom (e.g., gold, oxygen)—a cookie has many substances.

Compound

Mineral

¸?• Ç

+ A compound has atoms chemically bonded in fixed ratios (e.g., water = H₂O)—ingredients in cookies are not chemically bonded. + Minerals are naturally occurring inorganic solids, not human-made baked goods.

Visual Comparison:

Type of Matter

Definition

Example

Element

Only one type of atom

Oxygen (O₂), Gold (Au)

Compound

Chemically bonded elements in a fixed ratio

Mixture

Physically blended substances, not chemically bonded

Water (H₂O), Salt (NaCl) Cookie, salad, air

● Real-Life Application: Understanding mixtures is crucial in: •

Food science (e.g., baking cookies or cakes),

•

Pharmaceuticals (e.g., mixing drugs with fillers),

•

Environmental science (e.g., pollution in air or water mixtures).

✓ Summary Breakdown: ⬛

Component

Explanation

Correct Answer

⬛ Mixture ✓

Main Concept

A chocolate chip cookie has physically mixed parts that are not chemically bonded

Why It’s Right

It’s a classic example of a heterogeneous mixture

Misconception Fixed

Compounds are bonded chemically; mixtures are not

^ Question 37 " Question: Which example describes a compound? ⬛ Correct Answer: A substance with sodium atoms bonded to chlorine atoms ✓

□ Topic: ]L Pure Substances – Elements vs. Compounds (Section 2.3: Elements, Compounds, and Mixtures)

C What is this question testing? ç ' This question is assessing your understanding of: •

The definition of a compound in chemistry,

•

How atoms bond to form chemical substances with fixed ratios,

•

The difference between elements, compounds, and mixtures.

⬛ Why this answer is correct: ✓ A compound is a pure substance made from two or more different elements that are chemically bonded in a fixed ratio.

In this case:

•

Sodium (Na) and Chlorine (Cl) chemically bond to form sodium chloride (NaCl) — also known as table salt.

•

This is a classic compound because: o

It has a fixed chemical formula.

o

The atoms are chemically bonded.

o

It has new properties different from its individual elements.

+ Why the other choices are incorrect: Incorrect Option A substance with only iron atoms A substance with ffuorine and nitrogen atoms that are not bonded together

Why It’s Incorrect + This is an element, not a compound—only one kind of atom is present. + This is a mixture, not a compound—no chemical bonds between different atoms.

+ Another example of a mixture, not a A substance with iron and aluminum compound—no chemical combination atoms that are not bonded to each other involved.

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Visual Reference:

Compound vs. Mixture: Compound

Mixture

Chemically combined atoms

Physically mixed substances

Fixed ratio of elements

Variable composition

New substance with unique properties Keeps individual component properties Ex: NaCl (salt)

^" More Compound Examples:

Ex: Salt + pepper

•

H₂O – water (hydrogen + oxygen)

•

CO₂ – carbon dioxide (carbon + oxygen)

•

CH₄ – methane (carbon + hydrogen)

Each has different atoms bonded together in a specific, unchanging ratio.

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ A substance with sodium atoms bonded to chlorine atoms

Main Concept

Compounds are made of different atoms bonded together in a fixed ratio

Why It’s Right

NaCl is a perfect example of a compound, not a mixture or element

Misconception Fixed

Atoms must be bonded to be a compound—just being present together isn’t enough

↓n' Question 38 Question: In which state of matter are particles close together, but able to slide past one another? ✓ Correct Answer: Liquid ⬛

□ Topic: ] L States of Matter – Particle Behavior (Section 2.1: Properties of Matter)

C What is this question testing? ' ç This question checks your ability to: •

Understand the physical behavior of particles in different states of matter,

•

Recognize how particle spacing and movement affect properties like flow and shape.

✓ Why this answer is correct: ⬛ In the liquid state: •

Particles are close together, which is why liquids have a definite volume.

•

However, particles are not in fixed positions—they can slide past one another, allowing the liquid to flow and take the shape of its container.

•

This movement is what makes liquids fluid but not compressible.

+ Why the other choices are incorrect: Incorrect Option

Why It’s Incorrect

Solid

+ In solids, particles are closely packed and locked in place—they vibrate but don’t slide.

Plasma

+ Plasma is a high-energy state where particles are far apart and ionized—they do not slide.

Gas

+ Gas particles are far apart and move freely in all directions—they don’t slide past because they rarely touch.

_ Particle Arrangement Summary: :H State Particle Spacing Movement

Shape/Volume

Solid

Definite shape C volume

Very close

Vibrate only

Liquid Close, but not fixed Slide past each other No fixed shape; fixed volume Gas

Far apart

Plasma Very far C ionized

_ Fun Fact: n • . †

Move freely

No fixed shape or volume

High-energy motion

Like gas but with charged particles

Liquids are incompressible due to tight particle packing, which is why hydraulic systems (like car brakes) use liquids to transmit force efficiently.

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ Liquid

Main Concept

Liquids have particles close together but can move past each other

Why It’s Right

This structure allows liquids to flow while still having a definite volume

Misconception Fixed

Solids are rigid; gases/plasmas are far apart and don’t have sliding interactions

⬛» Question 3G Question: Which change of state does the image show?

(Note: From your correction doc, the answer is based on recognizing particle transitions.) ⬛ Correct Answer: Solid to liquid ✓

L Topic: ] □ States of Matter – Phase Changes (Section 2.1: Properties of Matter)

' çC

What is this question testing?

This question tests your ability to: •

Identify and name phase changes between different states of matter,

•

Understand particle behavior and energy input during these transitions.

✓ Why this answer is correct: ⬛

A change from solid to liquid is called melting. Here's why this fits: •

In a solid, particles are tightly packed and vibrate in place.

•

As thermal energy (heat) is added, the particles begin to vibrate more and eventually overcome their rigid structure.

•

This causes the solid to melt into a liquid, where particles are still close but can move past each other.

This is a physical change and is reversible.

+ Why the other choices are incorrect: Incorrect Option Why It’s Incorrect Liquid to gas

+ This is called evaporation or boiling, not melting.

Gas to solid

+ This is called deposition, the opposite of sublimation.

Gas to liquid

+ This is condensation, not what happens when a solid melts.

↓n' Phase Change Summary: Change

Name

Solid → Liquid Melting

Requires or Releases Heat?

Requires heat (endothermic)

Liquid → Gas Boiling/Evaporation Requires heat (endothermic) Gas → Liquid Condensation

Releases heat (exothermic)

Liquid → Solid Freezing

Releases heat (exothermic)

Solid → Gas Sublimation

Requires heat

Gas → Solid

Releases heat

Deposition

"^ Real-Life Examples of Melting: •

Ice turning into water.

•

Butter melting in a pan.

•

Chocolate melting in your hand.

Each involves thermal energy breaking rigid particle structure.

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ Solid to liquid

Main Concept

Melting is a phase change involving heat and change in particle motion

Why It’s Right

Solid particles gain energy, overcome attraction, and transition to liquid form

Misconception Fixed

Other answers describe different phase changes not seen in the image

µ Question 40 f ˛ Question: Which action demonstrates a chemical change? ✓ Correct Answer: Cooking an egg ⬛

□ Topic: ] L Physical vs. Chemical Changes (Section 2.1: Properties of Matter)

'çC

What is this question testing?

This question tests your ability to: •

Distinguish between chemical changes and physical changes,

•

Recognize that chemical changes form new substances with new properties,

•

Understand observable evidence of a chemical reaction.

✓ Why this answer is correct: ⬛ Cooking an egg is a chemical change because: •

The proteins in the egg white and yolk denature and recombine to form new substances.

•

This change is not reversible by physical means (you can't "uncook" an egg).

•

The change involves energy (heat) and results in a permanent change in chemical composition.

In other words, heat causes new molecules to form—this is a key feature of a chemical change.

+ Why the other choices are incorrect: Incorrect Option

Why It’s Incorrect

Shredding paper

+ This is a physical change—the paper’s form changes, but it’s still paper.

Evaporating water

+ This is a physical change—water changes state (liquid → gas), but remains H₂O.

Breaking a stick

+ This is a physical change—the stick is now in smaller pieces, but no new substance formed.

"^

Chemical vs. Physical Change Cheat Sheet:

Change Type Definition Chemical Change

New substance formed with new properties

Example

New Substance?

Cooking, rusting, burning

⬛ ✓ Yes

Change Type Definition

Example

Physical Change

Melting, freezing,

Change in shape, size, or state

tearing

New Substance? + No

?•¸Ç Evidence of Chemical Change: •

Color change

•

Gas production (bubbles/fizzing)

•

Heat or light release

•

Formation of a solid (precipitate)

•

Irreversibility

Cooking eggs shows color change, heat absorption, and irreversibility — all signs of chemical change.

⬛ ✓ Summary Breakdown: Component

Explanation

Correct Answer

⬛ ✓ Cooking an egg

Main Concept

A chemical change results in new substances that are irreversible

Why It’s Right

Cooking changes the egg’s chemical structure via heat

Misconception Fixed

Physical changes (e.g., shredding or evaporating) don’t make new materials

" Question 41 ^ Question: Which type of bond is formed when similar electrons are shared between two atoms? ✓ Correct Answer: Covalent ⬛

]L Topic: □ Chemical Bonding – Types of Bonds (Section 2.5: Bonding and Chemical Reactions)

ç What is this question testing? ' C This question is testing your ability to: •

Identify the types of chemical bonds,

•

Understand how valence electrons behave in each bond type,

•

Know the distinction between ionic, covalent, metallic, and other types of bonds.

✓ Why this answer is correct: ⬛ A covalent bond forms when two atoms share valence electrons. This usually occurs between: •

Two nonmetals,

•

Who both need to gain electrons to complete their outer shells.

By sharing, each atom gets a stable configuration, usually resembling a full octet (8 valence electrons).

Examples of covalent bonding: •

H₂O (water): Oxygen shares electrons with two hydrogen atoms.

•

CO₂ (carbon dioxide): Carbon shares electrons with two oxygen atoms.

+ Why the other choices are incorrect: Incorrect Option

Why It’s Incorrect

Ionic

+ In ionic bonds, electrons are transferred, not shared. Typically occurs between a metal and a nonmetal (e.g., NaCl).

Incorrect Option

Why It’s Incorrect

Mechanical

+ Mechanical bonding isn't a chemical bond—it's a physical connection (e.g., screws, adhesives). + In metallic bonds, valence electrons are free to move in a "sea of electrons" shared among many metal atoms—not a covalent pairwise sharing.

Metallic

Bond Type Summary:

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Bond Type How Electrons Behave

Common Between Example

Covalent Electrons are shared

Nonmetal + Nonmetal H₂O, CO₂

Ionic

Electrons are transferred

Metal + Nonmetal

Metallic

Electrons move freely in a "sea" Metal + Metal

Visual Aid:

¸?• Ç

mathematica Copy Covalent Bond: H

H

\ / O-O / \ H

H

(Atoms share electrons)

✓ Summary Breakdown: ⬛

NaCl Copper, Gold

Component

Explanation

Correct Answer

⬛ ✓ Covalent

Main Concept

Covalent bonds are formed by sharing electrons, typically between nonmetals

Why It’s Right

Shared electrons help atoms complete their valence shells, creating stable molecules

Misconception Fixed

Ionic = transfer; covalent = sharing; metallic = delocalized movement

^ Question 42 " Question: Which properties will elements in group 2 share, based on location in the periodic table?

Choose 2 answers ✓ Correct Answers: ⬛ •

Good thermal conductivity

•

Good electrical conductivity

L Topic: ] □ Periodic Table – Groups and Element Properties (Section 2.4: The Periodic Table)

ç'C What is this question testing?

This question tests your ability to: •

Understand how element groups (columns) on the periodic table share similar properties,

•

Know that Group 2 (alkaline earth metals) includes metals with similar physical and chemical behaviors,

•

Identify characteristics of metals, particularly conductivity.

⬛ Why these answers are correct: ✓ Group 2 elements, known as the alkaline earth metals (like beryllium, magnesium, calcium, etc.), are: •

•

Metals, and like most metals, they: o

Conduct heat well (good thermal conductivity),

o

Conduct electricity well (good electrical conductivity),

They are fairly reactive, though not as much as Group 1 (alkali metals).

These are inherent physical properties of metals due to their mobile valence electrons that facilitate energy and electron flow.

+ Why the other choices are incorrect: Incorrect Option

Why It’s Incorrect

Poor thermal conductivity

+ Group 2 elements are metals, and metals do not insulate heat—this is false.

Poor electrical conductivity

+ Metals are excellent electrical conductors—this directly contradicts their properties.

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Periodic Table Group Summary:

Group Name

Properties

1

Alkali Metals

Highly reactive, soft, conduct heat and electricity well

2

Alkaline Earth Metals Less reactive than Group 1, conduct heat C electricity well

17

Halogens

Very reactive nonmetals

18

Noble Gases

Nonreactive, full valence shell

•?¸Ç Real-Life Applications: •

Calcium (Ca): Essential for bones and used in cement.

•

Magnesium (Mg): Used in fireworks and aerospace materials because it's light and conductive.

•

Beryllium (Be): Used in electronics due to high electrical and thermal conductivity.

⬛ ✓ Summary Breakdown: Component

Explanation

Correct Answers ✓ ⬛ Good thermal conductivity, ⬛ ✓ Good electrical conductivity Main Concept

Group 2 elements are metals, which are good conductors

Why It’s Right

Metals allow free movement of heat and electrons—making them good conductors

Misconception Fixed

Not all elements are poor conductors—metals are the opposite, especially Group 2

" Question 43 ^ Question: Consider the location of sodium (Na) on the periodic table.

Which element has chemical properties that are similar to sodium's? ✓ Correct Answer: Potassium (K) ⬛

□ Topic: ] L Periodic Table – Element Families and Group Trends (Section 2.4: The Periodic Table)

ç 'C

What is this question testing?

This question tests your understanding of: •

How the periodic table is organized by chemical behavior,

•

Why elements in the same group (vertical column) have similar properties,

•

The behavior of alkali metals, particularly sodium and potassium.

✓ Why this answer is correct: ⬛ Sodium (Na) and Potassium (K) are both found in Group 1 of the periodic table, also known as the alkali metals.

•

These elements each have 1 valence electron, which makes them highly reactive—especially with water.

•

They have similar chemical properties, such as: o

Reactivity with halogens,

o

Ability to form +1 ions (Na⁺, K⁺),

o

Softness and metallic luster,

o

Low ionization energy.

Because potassium is directly below sodium in Group 1, it has similar but slightly more intense reactivity due to its larger atomic size.

+ Why the other choices are incorrect: Incorrect Option

Why It’s Incorrect

Beryllium (Be)

+ Beryllium is in Group 2 (alkaline earth metals). It has 2 valence electrons and does not react like sodium.

Neon (Ne)

+ Neon is a noble gas in Group 18. It has a full outer shell (8 electrons) and is completely unreactive.

Chlorine (Cl)

+ Chlorine is a halogen in Group 17. It has 7 valence electrons and is highly reactive—but in a very different way than sodium. In fact, Na and Cl react with each other to form NaCl (table salt).

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Visual Summary:

Element

Group

Valence Electrons Chemical Reactivity

Sodium (Na)

Group 1 1

Highly reactive (alkali)

Potassium (K) Group 1 1

⬛ Similar reactivity ✓

Beryllium (Be) Group 2 2

Moderately reactive metal

Chlorine (Cl)

Group 17 7

Reactive nonmetal (forms salts with Na)

Neon (Ne)

Group 18 8

Stable and unreactive gas

µ Real-Life Application: f˛ •

Sodium and potassium are both essential to biological systems (like nerve conduction and muscle contraction),

•

They are also dangerous in pure form, reacting explosively with water.

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ Potassium (K)

Main Concept

Elements in the same group have similar chemical properties

Why It’s Right

Potassium and sodium both belong to Group 1 alkali metals with 1 valence electron

Misconception Fixed

Proximity in the table doesn’t always mean similarity—groups matter more than rows

Question 44 Question: A beaker contains 500 g of liquid water. An ice cube with a mass of 5 g is added to the water in the beaker.

How many grams of liquid water are in the beaker when the ice has melted? ⬛ Correct Answer: 505 g ✓

]L Topic: □ Law of Conservation of Mass / Phase Changes (Section 2.1: Properties of Matter)

C What is this question testing? ç ' This question checks your understanding of: •

The conservation of mass during physical changes (melting),

•

The idea that matter is neither created nor destroyed in a physical process,

•

How mass is conserved during phase changes (solid → liquid).

✓ Why this answer is correct: ⬛ The ice cube is made of water in solid form. When it melts: •

It turns into liquid water, not a different substance.

•

Its mass doesn’t change; it's simply converted from one state to another.

•

The total liquid water = original water + melted ice → 500 g + 5 g = 505 g

So the final amount of liquid water is 505 grams.

+ Why the other choices would be incorrect (if present): Wrong Choice Example

Why It Would Be Incorrect

500 g

+ This ignores the mass of the ice cube—matter cannot disappear.

4S5 g

+ Mass cannot decrease when melting occurs.

More than 505 g

+ No additional matter is added—just the 5 g of ice turns to water.

^ Key Science Principle: " Law of Conservation of Mass "Mass cannot be created or destroyed in a physical or chemical change."

This means: •

When ice melts, its mass is conserved.

•

It adds to the liquid water already present.

_: Real-Life Example: H If you add an ice cube to a glass of water and come back later, the total volume increases slightly as the ice melts, but the mass of the water system stays the same — just in a different state.

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ 505 g

Main Concept

Mass is conserved during melting (solid → liquid)

Why It’s Right

The 5 g ice cube becomes 5 g of liquid water, adding to the original 500 g

Misconception Fixed

Melting is not mass loss—no matter is gained or lost, just changed in form

O Question 45 ● Question: A chemist places 250 grams of liquid water into a beaker. The volume of the liquid water is 250 milliliters. The chemist then freezes the water. After it is frozen, the ice has a volume of 273 milliliters.

What is the mass of the ice?

✓ Correct Answer: 250 grams ⬛

□ Topic: ] L Law of Conservation of Mass / Physical Changes (Section 2.1: Properties of Matter)

C What is this question testing? ç ' This question is assessing your understanding of: •

The difference between mass and volume,

•

How phase changes (like freezing) affect volume but not mass,

•

Application of the law of conservation of mass to a physical change.

✓ Why this answer is correct: ⬛ •

The mass of the water stays the same before and after freezing.

•

Freezing is a physical change—no atoms are added or lost.

•

Although the volume increases (273 mL vs. 250 mL), the mass remains constant at 250 grams.

•

This occurs because ice is less dense than liquid water, which is why it expands.

So, the mass of the frozen ice is still 250 grams.

+ Why the other choices would be incorrect (if present): Wrong Option Example

Why It’s Incorrect

273 grams

+ Volume increased, but mass did not—they are not the same property.

Less than 250 grams

+ Freezing does not make mass disappear—it only spreads it over more space.

Wrong Option Example More than 273 grams

Y

Why It’s Incorrect + No additional substance was added—this would violate conservation of mass.

Key Concept:

Law of Conservation of Mass "In a closed system, mass is conserved during any physical or chemical change." n_•† Even though ice takes up more space than liquid water (greater volume), it’s still made . of the same molecules—just rearranged in a solid crystalline structure.

¿● Real-Life Application: •

Ice floats in water because it is less dense.

•

1 mL of water = 1 gram in liquid form, but frozen water expands in volume while keeping the same mass.

⬛ ✓ Summary Breakdown: Component

Explanation

Correct Answer

⬛ 250 grams ✓

Main Concept

Mass is conserved during freezing—even if volume changes

Why It’s Right

The number of water molecules stays the same; they just rearrange in solid form

Misconception Fixed

Increased volume ≠ increased mass; density changes, not total matter

" Question 46 ^ Question: When baking soda is added to vinegar, a chemical reaction occurs. The reaction produces

carbon dioxide gas, and a liquid solution consisting mostly of water and a salt called sodium acetate.

How is mass affected in this reaction, according to the law of conservation of matter? ⬛Correct Answer: ✓ The total mass of the products is equal to the total mass of the reactants.

□ Topic: ] L Law of Conservation of Matter (Section 2.2: Changes in Matter)

' çC

What is this question testing?

This question tests your ability to: •

Apply the law of conservation of matter (mass) to a chemical reaction,

•

Understand that mass is conserved even when gas is produced or substances change form,

•

Recognize that chemical reactions rearrange atoms, but do not create or destroy them.

✓ Why this answer is correct: ⬛ According to the Law of Conservation of Matter: “Matter is neither created nor destroyed in a chemical reaction.”

•

In this reaction, baking soda (solid) and vinegar (liquid) react to form: o

Carbon dioxide gas (CO₂),

o

A liquid solution of water and sodium acetate.

Even though the products have a different form, the total mass of all the products equals the mass of the original reactants—assuming the reaction occurs in a closed system where the gas can’t escape.

+ Why the other choices (if given) would be incorrect:

Incorrect Response

Why It’s Incorrect

Mass increases due to gas formation

+ Gases don’t create extra mass—they are formed from the atoms in the reactants.

Mass decreases because gas escapes

+ That would only appear to happen in an open system.

The actual mass is still equal.

New matter is created

" ^

+ Matter is rearranged, not created—no new atoms appear.

Real-Life Chemistry:

This reaction is the classic vinegar + baking soda volcano:

Y

•

You see bubbling due to CO₂ gas being released.

•

If you performed it in a sealed container on a scale, the mass before and after would be the same.

Conservation Equation Format:

Reactants → Products NaHCO₃ (baking soda) + CH₃COOH (vinegar) → CO₂ + H₂O + CH₃COONa (sodium acetate) ✓ Every atom present on the left exists on the right — just rearranged. ⬛

⬛ ✓ Summary Breakdown: Component

Explanation

Correct Answer

✓ The total mass of the products is equal to the total mass of ⬛ the reactants.

Main Concept

The Law of Conservation of Matter — atoms are rearranged, not created or lost

Component

Explanation

Why It’s Right

Even if a gas is produced or a phase changes, the total number of atoms (mass) remains the same

Misconception Fixed

Gases aren’t “lost” if you're observing total system mass — mass is conserved

˛ Question 47 µ f Question: In which phase change is energy being absorbed from the surroundings? ✓ Correct Answer: Water boiling on an electric burner ⬛

] Topic: L □ Phase Changes s Energy Transfer (Section 2.1: Properties of Matter)

C What is this question testing? ç ' This question checks whether you understand: •

Which phase changes are endothermic (absorb heat),

•

Which phase changes are exothermic (release heat),

•

The energy flow between a substance and its surroundings during state changes.

✓ Why this answer is correct: ⬛ Boiling is the phase change from liquid to gas.

For this to happen: •

The substance must absorb energy (heat) from its surroundings (in this case, the electric burner),

•

That energy breaks intermolecular forces and allows molecules to escape into the gas phase.

Therefore, boiling is an endothermic process — it requires energy input.

+ Why the other choices are incorrect: Choice

Explanation

A. A pond freezing over in winter

+ Freezing is exothermic — the water releases heat into the environment as it becomes solid.

C. Molten glass + Solidifying (liquid → solid) is also exothermic — energy is solidifying into a vase released as particles lock into place.

D. Clouds forming on a summer day

+ This process involves condensation (gas → liquid), which is exothermic — water vapor releases energy as it forms droplets.

"^ Visual Summary of Energy in Phase Changes: Phase Change

Direction

Energy Flow Type

Boiling (B)

Liquid → Gas Absorbed

⬛ ✓ Endothermic

Freezing (A)

Liquid → Solid Released

+ Exothermic

Solidifying (C)

Liquid → Solid Released

+ Exothermic

Condensation (D) Gas → Liquid Released

+ Exothermic

C Memory Tip: 'ç "Boiling, Melting, and Subliming Suck Heat In." → That’s your reminder that these three are endothermic.

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ B. Water boiling on an electric burner

Component

Explanation

Main Concept

Boiling is endothermic — energy is absorbed to break bonds

Why It’s Right

The system pulls in heat to convert water into vapor

Misconception Fixed

Other phase changes here (freezing, condensation, solidifying) release energy

('•

Corrected Question 48

Question: What happens when wet clothes dry outside on a warm day?

Answer Choices: A. The water in the clothes absorbs energy from the air and becomes a gas.

B. The water in the clothes releases energy into the air and becomes a gas.

C. The air absorbs energy from the water and changes the water into a gas.

D. The air releases energy into the clothes and changes into liquid water. ⬛Correct Answer: ✓ A. The water in the clothes absorbs energy from the air and becomes a gas.

□ ] Topic: L Phase Changes – Evaporation s Energy Transfer (Section 2.1: Properties of Matter)

C ' What is this question testing? ç This question evaluates your understanding of: •

The energy transfer involved in evaporation,

•

The direction of energy flow during the drying of wet clothes,

•

The concept that water becomes gas (vapor) by absorbing heat from its surroundings.

✓ Why this answer is correct: ⬛ When clothes dry:

•

Water molecules in the fabric absorb thermal energy (heat) from the warm air and sun,

•

This energy increases the motion of the water molecules until they overcome intermolecular forces,

•

The water changes from liquid to gas (evaporation),

•

This is an endothermic process (requires absorption of heat).

⬛ Therefore, the correct process is: ✓ Water absorbs energy → Water molecules become vapor → Clothes dry

+ Why the other choices are incorrect: Incorrect Option B. The water in the clothes releases energy into the air and becomes a gas

Why It’s Incorrect + This reverses the energy flow. In evaporation, water must absorb, not release, energy.

C. The air absorbs energy from + The air isn’t absorbing the energy — the water is. the water and changes the Water needs to absorb energy to evaporate. water into a gas D. The air releases energy into + The air is not changing phase, and it does not the clothes and changes into become liquid water. That would describe condensation, liquid water which is the opposite of evaporation.

µ˛f Key Concept: Evaporation = Liquid → Gas, endothermic process •

Heat is absorbed by the liquid from the environment,

•

This gives molecules enough energy to escape into the air.

n Real-Life Analogy: ↓' •

After swimming, your skin feels cold as water evaporates.

•

This is because evaporation absorbs heat from your body and surroundings, cooling you down.

⬛ Summary Breakdown: ✓ Component

Explanation

Correct Answer

⬛ ✓ The water in the clothes absorbs energy from the air and becomes a gas.

Main Concept

Evaporation is an endothermic process that removes water by converting it to gas

Why It’s Right

Water molecules in the clothes need to absorb energy to evaporate and dry the fabric

Misconception Fixed

Water does not release energy to evaporate, and air does not turn into water

? Question 4G ● Question: Earth formed from dust and gases surrounding the sun.

Which force pulled the dust and gases together to form Earth? ⬛Correct Answer: ✓ Gravitational

□ Topic: ] L Forces and Planetary Formation (Section 3.2: Gravity in Space)

Cç What is this question testing? ' This question tests your understanding of: •

The role of fundamental forces in space,

•

How planets form from interstellar dust and gas in a process called accretion,

•

Why gravity, not other forces like magnetism or friction, is the dominant force in large-scale celestial structures.

✓ Why this answer is correct: ⬛ The process by which Earth (and other planets) formed is called gravitational accretion: •

After the Sun formed, leftover dust and gas began to clump together,

•

Gravity pulled these particles toward one another,

•

As more mass accumulated, the gravitational pull increased, leading to the formation of planetesimals, then protoplanets, and eventually Earth.

⬛ Gravity is the only force strong enough and far-reaching enough to gather material on ✓ this scale.

+ Why the other options are incorrect: Incorrect Option

Why It’s Incorrect

Electrical

+ Electrical forces act on charged particles and are not dominant at planetary scales.

Magnetic

+ Magnetic forces affect specific materials like iron and don’t attract neutral dust.

Frictional

+ Friction occurs between surfaces, but space is mostly a vacuum— no medium for friction.

Y Ç

Visual Concept:

Here’s a basic version of what happened: 1. Sun forms from a collapsing cloud of gas.

2. Leftover dust C gas orbit the sun in a disk.

3. Gravity pulls particles together → clumps.

4. Clumps grow → planetesimals → protoplanets → Earth. ⬛ None of this could happen without gravity. ✓

" Related Concept: ^ •

Newton’s Law of Universal Gravitation:

"Every mass attracts every other mass in the universe with a force proportional to the product of their masses and inversely proportional to the square of the distance between them."

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ Gravitational

Main Concept

Gravity is the dominant force in forming planets from space dust and gas

Why It’s Right

Gravity attracts all matter and drives accretion, the key process in planet formation

Misconception Fixed

Forces like magnetism and friction are not effective at large cosmic scales

YÇ

Question 50

Question: A galaxy consists of many stars in the same large region of space.

Which phenomenon leads stars to group together to form a galaxy? ⬛ ✓ Correct Answer: Gravity between stars

] Topic: L □ Forces in Space / Formation of Large Structures (Section 3.2: Gravity in Space)

'Cç What is this question testing?

This question tests your understanding of: •

The role of gravity as the dominant force on cosmic scales,

•

How galaxies and stellar systems form and are held together,

•

The difference between fundamental forces like gravity and nuclear or electric forces in terms of range and scale.

⬛ Why this answer is correct: ✓ Gravity is the only force strong enough over vast distances to: •

Pull together stars, dust, and gas,

•

Form galaxies, clusters, and superclusters,

•

Keep stars orbiting a common center of mass, such as a black hole or galactic core.

Even though gravity is the weakest of the four fundamental forces, it: •

Acts on all matter (regardless of charge),

•

Has an infinite range,

•

Becomes dominant when dealing with huge masses, like stars and galaxies.

✓ So stars group into galaxies due to the gravitational attraction between them. ⬛

+ Why the other options are incorrect: Incorrect Option

Why It’s Incorrect

Electrical attraction

+ Electric forces only act on charged particles. Stars are overall electrically neutral.

Random coincidence

+ Stars don’t just “happen” to group together. The grouping is caused by a force, not chance.

Incorrect Option

Why It’s Incorrect

Nuclear force between ions

+ Nuclear force acts at subatomic distances—only within atoms or nuclei—not across space.

Fc

Visual Analogy:

Imagine gravity like an invisible net: •

It pulls stars toward each other,

•

Stars orbit within galaxies due to the collective gravitational pull,

•

Without gravity, stars would just drift away through space.

" Related Concept: ^ •

Galaxy Formation Theory: After the Big Bang, gravity caused clumps of matter to collapse and form stars, then galaxies.

•

Even dark matter is thought to shape galaxies through gravitational effects.

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ Gravity between stars

Main Concept

Gravity is the only long-range force strong enough to group stars together

Why It’s Right

Gravity causes formation and structure of galaxies and star systems

Misconception Fixed

Galaxies are not random, and nuclear/electric forces don’t act over long distances

●l Corrected Question 51

Question: Which season is it in Japan and in Australia when Earth is in the position shown in the diagram?

Answer Choices: A. Summer in both Japan and Australia B. Winter in both Japan and Australia C. Winter in Japan and summer in Australia D. Summer in Japan and winter in Australia ⬛ ✓ Correct Answer: C. Winter in Japan and summer in Australia

□ Topic: ] L Seasons and Earth’s Tilt (Section 3.3: Earth in Space)

ç'C What is this question testing?

This question is testing your understanding of: •

The tilt of Earth’s axis (about 23.5°),

•

How Earth’s position in its orbit causes opposite seasons in the Northern and Southern Hemispheres,

•

Basic geographic knowledge: o

Japan is in the Northern Hemisphere,

o

Australia is in the Southern Hemisphere.

✓ Why this answer is correct: ⬛ When the Earth is positioned so that the Southern Hemisphere is tilted toward the Sun: •

It’s summer in Australia (Southern Hemisphere),

•

It’s winter in Japan (Northern Hemisphere).

This is due to the angle of sunlight: •

The hemisphere tilted toward the Sun gets more direct sunlight → summer,

•

The hemisphere tilted away gets less sunlight → winter.

⬛ So if the diagram shows Earth tilted with the South Pole toward the Sun, then: ✓ •

Australia = summer

•

Japan = winter

+ Why the other answer choices are incorrect: Incorrect Option

Why It’s Incorrect

A. Summer in both Japan and Australia

+ Opposite hemispheres can’t have summer at the same time. One is always tilted away.

B. Winter in both Japan and Australia

+ Same issue — the seasons are always opposite between hemispheres.

Incorrect Option

Why It’s Incorrect

D. Summer in Japan and winter in Australia

+ This would happen when Northern Hemisphere is tilted toward the Sun, not the south.

● Key Concept: ?

Hemisphere Tilted Toward Season in Northern Sun Hemisphere

Season in Southern Hemisphere

Northern

Summer

Winter

Southern

Winter

Summer

✓ That’s why seasons are reversed between Japan and Australia. ⬛

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ Winter in Japan and summer in Australia

Main Concept

Earth’s tilt causes opposite seasons in Northern and Southern Hemispheres

Why It’s Right

When the Southern Hemisphere is tilted toward the Sun, Australia gets summer and Japan gets winter

Misconception Fixed

Both hemispheres do not share the same season — they are always opposite

+ · Question 52 • Question: What is true during summer in the Northern Hemisphere?

Answer Choices: A. Earth is closer to the sun than during the winter.

B. Earth rotates more slowly than in the winter.

C. The Northern Hemisphere receives more direct sunlight than in the winter.

D. The Northern Hemisphere is tilted less toward the sun than in the winter. ⬛Correct Answer: ✓ C. The Northern Hemisphere receives more direct sunlight than in the winter.

□ Topic: ] L Seasons and Earth's Tilt (Section 3.3: Earth in Space)

C What is this question testing? ç ' This question assesses your understanding of: •

The tilt of Earth’s axis and its effect on seasonal changes,

•

The angle of sunlight reaching each hemisphere throughout the year,

•

Why direct sunlight, not Earth’s distance from the Sun, determines the warmth and length of seasons.

✓ Why this answer is correct: ⬛ During summer in the Northern Hemisphere: •

The North Pole is tilted toward the Sun (about 23.5°),

•

This causes sunlight to strike the Northern Hemisphere more directly (at a higher angle),

•

As a result: o

Days are longer,

o

Temperatures are higher,

o

More solar energy is absorbed.

✓ The key factor here is sunlight angle, not distance from the Sun. ⬛

+ Why the other options are incorrect:

Incorrect Option

Why It’s Incorrect

+ In fact, Earth is slightly closer to the Sun during A. Earth is closer to the sun than Northern Hemisphere winter (early January). during the winter.

Distance has less impact than axial tilt.

B. Earth rotates more slowly than + Earth’s rotation speed stays nearly constant yearin the winter. round. Rotation affects day/night, not seasons.

D. The Northern Hemisphere is + It’s actually tilted more toward the Sun during tilted less toward the Sun than in summer, not less. This tilt is what causes the direct the winter. sunlight.

†ˇ`

Key Concept: Seasons Are Due to Tilt, Not Distance!

Season Hemisphere Tilted Toward Sun Sunlight Angle Daylight Hours Summer Yes

More Direct

Longer

Winter No

Less Direct

Shorter

"^

Bonus Fact: •

Earth’s orbit is slightly elliptical, but the difference in distance between summer and winter is not significant enough to cause the seasons.

•

It’s the axial tilt that makes all the difference.

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ The Northern Hemisphere receives more direct sunlight than in the winter.

Main Concept

Summer happens because the Northern Hemisphere is tilted toward the Sun

Component

Explanation

Why It’s Right

Direct sunlight = higher solar intensity = more warmth

Misconception Fixed

Seasons are not caused by distance from the Sun, and Earth’s rotation doesn’t change

? Question 53 ● Question: Which position on the diagram represents Earth's location in its orbit during winter at a weather station near Earth’s South Pole?

Answer Choices: A B C D ⬛ ✓ Correct Answer: A

□ ] L Topic:

Earth’s Orbit, Seasons, and Hemispheres (Section 3.3: Earth in Space)

C What is this question testing? ç ' This question tests whether you can: •

Apply your understanding of Earth’s axial tilt and orbital position to determine seasons in each hemisphere,

•

Identify when the Southern Hemisphere is tilted away from the Sun (which causes winter at the South Pole),

•

Interpret Earth’s position in orbit relative to the Sun and axial tilt.

✓ Why this answer is correct (likely Position B): ⬛ •

Four Earth positions around the Sun representing the solstices and equinoxes: o

Position A → June Solstice (NH = summer, SH = winter)

o

Position B → December Solstice (NH = winter, SH = summer)

o

Position C → March Equinox (both hemispheres = equal light)

o

Position D → September Equinox (both hemispheres = equal light)

So, if the question is asking: “Which position represents winter at a station near Earth’s South Pole?”

Then the South Pole must be tilted away from the Sun, which would happen in June (when it’s summer in the Northern Hemisphere). ⬛ That corresponds to Position A ✓ But—double check: •

If Position B shows the South Pole tilted toward the Sun, then it's summer at the South Pole.

•

If Position A shows the South Pole tilted away from the Sun, then it’s winter at the South Pole.

+ Common Mistakes (Why other options might be wrong):

Answer Option

Why It's Probably Incorrect

C

Likely a March equinox → both hemispheres get equal light → not winter at South Pole This shows Southern Hemisphere tilted toward the Sun → summer at the South Pole

D

Likely a September equinox → again, equal light → not deep winter

B

+ · • + Visual Clue (Typical Orbital Layout): Position Earth's Tilt Toward Sun Season in Southern Hemisphere A

Tilted away

⬛ ✓ Winter

B

Tilted toward

+ Summer

C

Sideways tilt (equinox) + Spring or Fall

D

Sideways tilt (equinox) + Spring or Fall

⬛ Summary Breakdown: ✓ Component

Explanation

Correct Answer

⬛ A shows the South Pole tilted away from the Sun ✓

Main Concept

Winter at the South Pole happens when Southern Hemisphere is tilted away

Why It’s Right

The angle of sunlight is the main factor in seasonal temperature differences

Misconception Fixed

Many think distance from Sun causes seasons — it’s actually axial tilt

?● Question 54 Question: A geologist is doing a risk assessment for a location where the African plate is moving away

from the South American plate.

Which risk description must the geologist give for this location?

Answer Choices: A. There is high risk of volcanoes and low risk of large earthquakes.

B. There is low risk of volcanoes and high risk of large earthquakes.

C. There is high risk of both volcanoes and large earthquakes.

D. There is low risk of both volcanoes and large earthquakes. ✓ Correct Answer: ⬛ A. There is high risk of volcanoes and low risk of large earthquakes.

□ Topic: ] L Plate Tectonics s Geologic Hazards (Section 3.1: Plate Tectonics)

'Cç What is this question testing?

This question checks your understanding of: •

The types of plate boundaries (divergent, convergent, transform),

•

The geologic activity commonly associated with divergent boundaries,

•

How plate movement influences volcanic and earthquake activity.

✓ Why this answer is correct: ⬛ The African Plate and the South American Plate are moving away from each other.

This is a divergent plate boundary — specifically, along the Mid-Atlantic Ridge.

At divergent boundaries: •

Magma rises up as the plates pull apart,

•

This creates volcanoes (typically along ocean ridges),

•

Earthquakes do occur, but they are generally shallow and less powerful than those at other types of boundaries.

⬛ ✓ So:

•

High risk of volcanoes ⬛ ✓

•

Low risk of large earthquakes ⬛ ✓

+ Why the other choices are incorrect: Incorrect Option

Why It’s Incorrect

B. Low risk of volcanoes and high + Opposite of the correct pattern. Large quakes are risk of large earthquakes more typical at transform or convergent boundaries.

C. High risk of both volcanoes and large earthquakes

+ While volcanoes are common, large quakes are not typical at divergent boundaries.

D. Low risk of both volcanoes and large earthquakes

+ Volcanoes are very common at divergent boundaries like the Mid-Atlantic Ridge.

5 Bonus Visual: ) „ Plate Boundary Type

Plates Do This

Divergent

Move apart

Convergent

Risk

Volcano Risk

Example

Low-moderate

⬛ High ✓

Mid-Atlantic Ridge

Move toward each other

Transform

Earthquake

Slide past each other

✓ ⬛ High

⬛ High ✓

Andes Mountains, ⬛ High ✓ Low

Himalayas San Andreas Fault (California)

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

✓ High volcano risk, low large earthquake risk ⬛

Component

Explanation

Main Concept

Divergent boundaries (plates moving apart) tend to form volcanoes, not large quakes

Why It’s Right

Magma rises as plates pull apart → volcanoes form; tectonic stress is lower

Misconception Fixed

Not all boundaries produce strong quakes — divergent ones typically don’t

O¡ Question 55 ' j e Question: A utility company is considering building a power plant at a location on the Eurasian plate far from any plate boundaries.

Which types of risk are present in this location?

Answer Choices: A. Low risk of volcanoes, high risk of earthquakes B. High risk of volcanoes, low risk of earthquakes C. Low risk of both volcanoes and earthquakes D. High risk of both volcanoes and earthquakes ⬛Correct Answer: ✓ C. Low risk of both volcanoes and earthquakes

□ Topic: ] L Plate Tectonics s Geologic Risk (Section 3.1: Plate Tectonics)

ç'C What is this question testing?

This question tests your understanding of: •

How tectonic plate boundaries are the main locations for geologic activity (earthquakes and volcanoes),

•

What conditions exist within the interior of tectonic plates,

•

Where it is safest to build critical infrastructure like power plants.

✓ Why this answer is correct: ⬛ If a location is: •

On the Eurasian Plate, and

•

Far from any plate boundaries,

Then it is located in the interior of a tectonic plate, also known as a stable continental region.

In such locations: •

There is little to no tectonic movement,

•

No plate collisions, sliding, or separation,

•

Resulting in very low risk of both: o

Earthquakes, and

o

Volcanic activity.

⬛ This makes interior plate regions ideal for stable infrastructure development. ✓

+ Why the other choices are incorrect: Incorrect Option

Why It’s Incorrect

A. Low risk of volcanoes, high risk of earthquakes

+ Earthquakes are mostly caused by movement at or near plate boundaries. Far from boundaries = low risk.

B. High risk of volcanoes, low risk of earthquakes

+ Volcanoes typically form at convergent or divergent boundaries, or over hot spots — not in the middle of plates.

D. High risk of both volcanoes and earthquakes

+ This is true near active plate boundaries, not far from them.

„5) Key Concept: Location Matters

Location Type

Volcano Risk Earthquake Risk Example

Near Convergent Boundary High

High

Japan, Indonesia

Near Divergent Boundary High

Low-Moderate

Mid-Atlantic Ridge

Near Transform Boundary

High

San Andreas Fault (California)

⬛ Low ✓

Siberia, Midwest USA

Low

Interior of Plate (far away) ✓ ⬛ Low

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ Low risk of both volcanoes and earthquakes

Main Concept

Interior areas of tectonic plates are geologically stable

Why It’s Right

No nearby boundaries → no fault zones or magma sources = low geologic hazard

Misconception Fixed

Earthquakes and volcanoes are not randomly distributed—they follow plate edges

) Corrected Question 56 „ 5 Question: The map shows some of Earth’s tectonic plates with the directions of plate motion indicated by arrows.

Which statement accurately describes these locations? ⬛Correct Answer: ✓ "Volcanoes are more likely at location C than at location A."

□ Topic: ] L Tectonic Plate Boundaries and Volcanic Activity (Section 3.1: Plate Tectonics)

ç'C What is this question testing?

This question tests whether you understand: •

The relationship between plate boundary types and volcanic activity,

•

How plate motion directions help identify convergent, divergent, and transform boundaries,

•

Why certain boundary types are more volcanically active than others.

✓ Why this answer is correct: ⬛ To say “volcanoes are more likely at location C than at location A” implies: •

Location C is at a divergent boundary (Low Mod Rsik of quakes and High risk of Volcanoes),

•

Location A is at a Interior of plate (low risk bc it’s far away from boundaries)

•

What happens at these boundary types?

•

Convergent boundaries: One plate is subducted under another → friction and melting create magma → volcanoes (e.g., Andes, Japan).

•

Divergent boundaries: Plates pull apart → magma rises through cracks → mid-ocean ridge volcanoes (e.g., Mid-Atlantic Ridge).

•

Transform boundaries: Plates slide past each other → no subduction, no magma, so no volcanoes (e.g., San Andreas Fault).

⬛ ✓ So if: •

C is at a divergent or convergent boundary

•

and A is at a transform boundary, then C has higher volcanic risk than A — which makes the answer correct.

+ Why the other choices are incorrect (based on typical diagrams): Statement

Why It’s Incorrect

Large earthquakes are more Possibly true if A is a transform fault—but we don't have likely at A than at B enough info to confirm.

Statement

Why It’s Incorrect

Neither earthquakes nor volcanoes are likely at B

Unlikely unless B is deep in the interior of a plate (not typical on boundary maps).

Both earthquakes and volcanoes are likely at D

Could be true if D is a convergent boundary, but this conflicts with C being more volcanic than A unless clearly labeled.

? Concept Recap: Volcano Formation ● Boundary Type Volcano Risk Why? Convergent

⬛ ✓ High

Subduction melts rock into magma

Divergent

⬛ ✓ High

Rising magma fills gaps as plates pull apart

Transform

+ Low

No melting, no magma, no volcanoes

Plate Interior

+ Very Low Far from magma sources

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ Volcanoes are more likely at location C than at location A

Main Concept

Volcanic activity depends on plate boundary type, not just plate movement

Why It’s Right

C is likely at a volcanically active boundary (convergent or divergent); A is likely transform

Misconception Fixed

Not all plate boundaries produce volcanoes — transform faults don’t

Ç Question 57 7 L ç

Question: A river ffows across a region. As the river ffows, it erodes the rock beneath it.

Which type of landform will develop if the river continues to ffow along a straight path?

Answer Choices: A. Valley B. Dune C. Glacier D. Meander ⬛Correct Answer: ✓ A. Valley

□ Topic: ] L Erosion and Landform Development (Section 3.4: Earth's Surface and Landforms)

C What is this question testing? ç ' This question evaluates your understanding of: •

How moving water shapes Earth’s surface,

•

The connection between erosion and landforms,

•

The features formed by river erosion depending on the river’s path.

✓ Why this answer is correct: ⬛ When a river flows in a straight path over time: •

It erodes the bedrock beneath it (vertical erosion),

•

This erosion deepens and carves out the landscape,

•

Over long periods, this process forms a valley.

There are two main types of valleys: •

V-shaped valleys → carved by rivers

•

U-shaped valleys → carved by glaciers

Since the question says “a river flows” and erosion occurs, the landform is: ✓ A valley—more specifically, a V-shaped valley caused by river erosion. ⬛

+ Why the other options are incorrect: Incorrect Option

Why It’s Incorrect

B. Dune

+ Dunes are formed by wind, not by flowing water. Common in deserts or beaches.

C. Glacier

+ Glaciers are masses of ice, not landforms. They create U-shaped valleys but aren't formed by rivers.

D. Meander

+ Meanders are curving bends in a river, not the result of a straight path.

The question specifically says the river flows in a straight line.

? Visual Example: ● Imagine a mountain stream carving its way downhill: •

Over time, it cuts deeper and deeper into the earth,

•

This creates a narrow, steep-sided valley — classic sign of river erosion.

⬛ ✓ Summary Breakdown: Component

Explanation

Correct Answer

⬛ ✓ Valley

Main Concept

Rivers erode land vertically, forming V-shaped valleys over time

Why It’s Right

A straight river path results in deepening erosion → formation of a valley

Misconception Fixed

Meanders form from curving rivers, not straight ones

🪨 Question 5G Question: Where is metamorphic rock found in the rock cycle?

Answer Choices: A. After erosion and deposition B. After folding and cracking C. After heat and pressure D. After melting and cooling ⬛Correct Answer: ✓ C. After heat and pressure

] Topic: L □ The Rock Cycle (Section 3.4: Earth’s Surface and Landforms)

ç 'C

What is this question testing?

This question checks your understanding of: •

The rock cycle,

•

How metamorphic rock forms,

•

The differences between sedimentary, igneous, and metamorphic rocks based on their processes.

✓ Why this answer is correct: ⬛ Metamorphic rocks form when: •

Existing rock (which can be sedimentary, igneous, or even another metamorphic rock)

•

Is subjected to intense heat and pressure,

•

Without melting.

This causes the minerals in the rock to reorganize and recrystallize, forming a new texture and structure, but not a liquid. ✓ So in the rock cycle: ⬛ •

Heat and pressure → Metamorphic rock

+ Why the other answer choices are incorrect: Answer Choice

Why It’s Incorrect

A. After erosion and deposition

+ That leads to sedimentary rock, not metamorphic. Erosion breaks rocks down → deposition lays down layers → pressure cements them.

B. After folding and + Folding/cracking may be part of tectonic movement but doesn’t cracking define how metamorphic rocks form.

D. After melting and cooling

+ That creates igneous rocks (magma or lava cools and hardens), not metamorphic.

⬛ Rock Cycle Recap » Process

Resulting Rock Type

Erosion → Deposition → Cementation Sedimentary Rock Melting → Cooling

Igneous Rock

Heat + Pressure (no melting)

⬛ ✓ Metamorphic Rock

Extreme Heat → Melting → Cooling Again Igneous again (starts cycle over)

" Bonus Tip: ^ •

The key distinction for metamorphic rocks is "no melting" — if it melts, it becomes magma and restarts the cycle.

•

Common metamorphic rocks:

o

Limestone → Marble

o

Shale → Slate

o

Granite → Gneiss

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ After heat and pressure

Main Concept

Metamorphic rocks are formed inside Earth under pressure and heat, not melted

Why It’s Right

Recrystallization of existing rock structure without melting

Misconception Fixed

Don’t confuse with melting (igneous) or sediment layers (sedimentary)

🪨 Question 60 Question: A student makes the diagram of the rock cycle that is shown here.

Which description should the student place on arrow A? (In other words: In order for a metamorphic rock to change into a sedimentary rock, what proce (Diagram is similar to this rock cycle diagram):

Answer Choices: A. Melting and cooling B. Heat and pressure C. Erosion and deposition D. Folding and cracking ⬛ ✓ Correct Answer: C. Erosion and deposition

□ Topic: ] L The Rock Cycle – Processes that Form Sedimentary Rock (Section 3.4: Earth's Surface and Landforms)

ç'C What is this question testing?

This question tests your ability to: •

Interpret arrows in a diagram of the rock cycle,

•

Know the processes that transform one rock type into another,

•

Match specific transformations with the correct geologic process (e.g., heat and pressure vs. erosion and deposition).

⬛ Why this answer is correct: ✓ In most standard rock cycle diagrams, Arrow A points from existing rock (igneous or metamorphic) → sedimentary rock.

To get sedimentary rock: 1. Any existing rock undergoes weathering and erosion → broken into sediments, 2. Sediments are transported and deposited, 3. Layers build up and undergo compaction and cementation → forms sedimentary rock. ⬛ So, Arrow A represents the process: ✓ Erosion and deposition → Sedimentary Rock

+ Why the other choices are incorrect: Answer Choice Why It’s Incorrect A. Melting and + This leads to igneous rock, not sedimentary. You’d see this arrow cooling pointing toward igneous, starting from magma.

B. Heat and pressure

+ This transforms rocks into metamorphic rock, not sedimentary.

+ This is a tectonic process, not a core part of the rock cycle D. Folding and transformation. It may lead to pressure but doesn’t explain sediment cracking formation.

● Rock Cycle Process Summary Table: ?‘ ●◯· Process

Forms Which Rock Type Key Mechanism

Erosion s Deposition ⬛ ✓ Sedimentary

Breakdown + transport + cementation

Heat s Pressure

Metamorphic

Mineral restructuring (no melting)

Melting s Cooling

Igneous

Magma solidifies

Weathering

Begins sediment cycle

Physical and chemical breakdown

"^

Tip for Test Day: •

If the arrow ends at "sedimentary rock", the process is always erosion and deposition.

•

If it ends at metamorphic rock, choose heat and pressure.

•

If it ends at igneous rock, choose melting and cooling.

⬛ Summary Breakdown: ✓ Component

Explanation

Correct Answer

✓ Erosion and deposition ⬛

Main Concept

This is the process where sediments form and settle to eventually make rock

Why It’s Right

Sedimentary rock forms from sediments, which come from erosion

Misconception Fixed

Melting doesn't create sedimentary rock — it starts the igneous cycle

? Quick Rock Cycle Review: ● Rock Type

Forms From

Sedimentary Sediment layers

Environment Surface: rivers, seas, deserts

Rock Type

Forms From

Environment

Igneous

Cooled magma or lava

Volcanic areas or deep underground

Metamorphic Any rock under heat + pressure Deep in crust, mountain building zones ç'C How to Recognize Environments by Rock Type: If you see…

Think…

Limestone on top of shale

Sea got shallower over time

Sandstone → shale → limestone Land to sea progression Granite beneath layers

Older magma chamber, uplifted

Fossils in rock

Likely sedimentary

Bands or crystals in a hard rock Metamorphic (heat + pressure) 🪨 Question 62 Question: The rock layers shown in the illustration have not been disturbed or overturned.

(From top to bottom: limestone → shale → sandstone → marble) What can be inferred about the geologic history of this area from these rock layers? ⬛Correct Answer: ✓ B. It was exposed to high heat and pressure, and then experienced deposition.

L Topic: □ ] Rock Cycle, Metamorphism, and Relative Dating (Section 3.4: Earth’s Surface and Landforms)

ç'C What is this question testing?

This question assesses your understanding of: •

Geologic sequencing (what happened first vs. later),

•

The formation of metamorphic rock (especially marble),

•

How younger sedimentary layers can be deposited on top of older metamorphic rock.

⬛ Why this answer is correct (with the updated logic): ✓ ⬛ Let’s rethink the sequence using this answer: “ 1. Marble is the lowest layer → meaning it formed first.

2. Marble is a metamorphic rock, meaning it was once a different rock (usually limestone) that was transformed by heat and pressure.

3. After the metamorphic rock formed, the area must have cooled, uplifted, or stabilized enough to allow new sedimentary deposition to happen on top of it: o

Sandstone → Shale → Limestone (deposited in that order).

✓ So, the correct sequence is: ⬛ 1. Heat and pressure → formation of marble 2. Followed by deposition of new sedimentary layers Which matches answer B exactly: “It was exposed to high heat and pressure, and then experienced deposition.”

+ Why the other choices are incorrect: Answer Choice A. Frequent volcanic eruptions C. It experienced deposition, then heat and pressure D. Magma chamber

Why It’s Incorrect + No volcanic (igneous) rock like basalt or obsidian is shown. + That would result in the upper sedimentary layers also being metamorphosed — but they’re not. + Magma chambers create igneous rock (e.g., granite), not marble, which is metamorphic.

ić: !f Rock Transformation Summary:

Process

Result

Heat s Pressure Metamorphic rock (e.g., limestone → marble) Later Deposition Sedimentary layers on top of metamorphic rock This combination is common in uplifted mountain ranges where old metamorphic basement rock is later buried under sediments.

⬛ ✓ Summary Breakdown: Component

Explanation

Correct Answer

✓ It was exposed to high heat and pressure, and then experienced ⬛ deposition

Main Concept

Metamorphic rocks can form before newer sedimentary layers are deposited

Why It’s Right

Marble formed first, then other rocks were laid down on top

Misconception Fixed

Metamorphism doesn’t always come after all other layers — it can come before sedimentation too

●? Corrected Question 63 Question: Through which layer of the atmosphere does a mountaineer climbing a tall mountain ascend?

Answer Choices: A. Troposphere B. Stratosphere C. Mesosphere D. Thermosphere ⬛Correct Answer: ✓ A. Troposphere

□ Topic: ]L

Earth’s Atmosphere and Its Layers (Section 3.2: Earth and Space Systems)

C What is this question testing? ç ' This question checks your understanding of: •

The structure of Earth’s atmosphere,

•

The altitudes of different atmospheric layers,

•

Where weather and human activity occur relative to those layers.

✓ Why this answer is correct: ⬛ The troposphere is the lowest layer of Earth's atmosphere. It extends: •

From Earth’s surface up to about 8–15 km (5–9 miles), depending on latitude,

•

Includes mountain elevations, airplanes, clouds, and all weather activity.

Even the tallest mountain in the world, Mount Everest (8.8 km / ~2G,000 ft), is entirely within the troposphere. ✓ So, a mountaineer ascending a tall mountain remains in the troposphere the entire ⬛ time.

+ Why the other answer choices are incorrect: Answer Choice Why It’s Incorrect B. Stratosphere

+ Begins around 10–15 km above sea level; used by jet aircraft and home of the ozone layer, but above mountain range heights.

C. Mesosphere

+ Begins around 50 km up; where meteors burn up, but far above any mountain.

D. Thermosphere

+ Starts around 80–100 km and includes auroras and the International Space Station — definitely not reachable by a mountaineer!

● Atmospheric Layers Overview (Low to High): Layer

Altitude Range Key Features

Troposphere 0–8 to 15 km

⬛ Weather, mountains, clouds, human life ✓

Stratosphere ~10–50 km

Ozone layer, jets, stable air

Mesosphere ~50–85 km

Meteors burn up here

Thermosphere ~85–600 km Auroras, satellites, space station

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ Troposphere

Main Concept

The troposphere includes Earth’s surface, all mountains, and weather

Why It’s Right

Mountaineers don’t climb above ~G km, which is well inside the troposphere

Misconception Fixed

Don’t confuse troposphere with stratosphere — planes go there, not people on foot

C Memory Tip: ç ' C “The Smart Man Took the Elevator” +.

Each first letter matches a layer from lowest to highest: •

T → Troposphere

•

S → Stratosphere

•

M → Mesosphere

•

T → Thermosphere

•

E → Exosphere (optional, but helps round it out)

3 Quick Feature Chart: s y [ / Layer

Height Range

Troposphere 0–15 km

Key Features

Memory Trigger

Weather, clouds, airplanes, '„n ?´ Where we live and climb mountains life, mountains

Stratosphere ~15–50 km Ozone layer, jet aircraft

´ Jet stream + S for Sun Shield (ozone)

Mesosphere ~50–85 km Meteors burn up

(ı ;C

Thermosphere Exosphere

~85–600

"M for Meteors burn here"

km

Auroras, satellites, space station

Y "T for Thermal / Ç Temperature rise" (very hot!)

600+ km

Edge of space

/ "E for Exit to space" ' ½˙•7. ¸

‘’,˙ Test Tip: f ) If you’re asked where planes ffy: stratosphere.

Where weather happens and people live: troposphere.

Where meteors burn up: mesosphere.

Where satellites and auroras are: thermosphere. £Ç̂ Question 64 Question: A meteorologist is studying the formation of a hurricane.

Which layer of the atmosphere is the meteorologist studying?

Answer Choices: A. Troposphere B. Stratosphere C. Mesosphere D. Thermosphere ⬛Correct Answer: ✓ A. Troposphere

□ Topic: ]L

Atmosphere Layers and Weather Phenomena (Section 3.2: Earth and Space Systems)

C What is this question testing? ç ' This question tests your understanding of: •

Where weather occurs,

•

The relationship between atmosphere layers and meteorology,

•

What layers are involved in different natural phenomena (e.g., hurricanes, auroras, meteors).

⬛ Why this answer is correct: ✓ All weather events — including hurricanes, thunderstorms, snow, and tornadoes — occur in the troposphere, which is: •

The lowest layer of Earth’s atmosphere,

•

Extends from Earth's surface up to about 8–15 km (5–G miles),

•

Contains about 75% of the atmosphere's mass and almost all of its moisture (essential for clouds and storms).

⬛ Since hurricanes form over warm ocean water, and involve air pressure, wind, and ✓ clouds, the meteorologist is studying the troposphere.

+ Why the other choices are incorrect: Answer Choice Why It’s Incorrect B. Stratosphere

+ Contains the ozone layer and is relatively stable — not involved in active weather systems like hurricanes.

C. Mesosphere

+ Too high up — where meteors burn up, not where storms or air masses interact.

D. + Much higher in altitude — where auroras and satellites are found, Thermosphere but not part of weather systems.

?● Atmospheric Layers + Roles (Recap): Layer

Altitude

What Happens There

Troposphere 0–15 km

✓ All weather, storms, hurricanes ⬛

Stratosphere 15–50 km

Ozone layer, jet planes, no weather

Mesosphere 50–85 km

Meteors burn

Thermosphere 85–600+ km Auroras, satellites, extreme temperature

'çC

Easy Way to Remember:

“Troposphere = Turbulent Weather” And meteorologists study weather, so it’s always the troposphere.

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ Troposphere

Main Concept

Hurricanes and weather only form in the lowest atmospheric layer

Why It’s Right

Contains moisture, wind, and heat needed for weather systems

Misconception Fixed

Higher layers like the stratosphere and thermosphere are not involved in weather

Question 65 Question: During heavy rains, the soil on a farm is washed away into a nearby river.

Which parts of the water cycle result in this loss of soil?

(Choose 2 answers) Answer Choices: A. Precipitation

B. Infiltration C. Runoff D. Evaporation ⬛ Correct Answers: ✓ A. Precipitation C. Runoff

□ Topic: ] L Water Cycle s Surface Processes (Section 3.2: Earth and Space Systems)

' çC

What is this question testing?

This question tests your ability to: •

Identify parts of the water cycle,

•

Understand how precipitation and surface water movement affect soil erosion,

•

Distinguish between infiltration, runoff, and evaporation in context.

✓ Why these answers are correct: ⬛ ⬛ A. Precipitation ✓ •

This is rainfall (or snow/hail), which adds water to the land surface.

•

In this case, heavy rains directly hit the soil, starting the erosion process.

•

Impact force of raindrops loosens soil particles.

⬛ ✓ C. Runoff •

After the rain falls, excess water flows over the land surface — this is called runoff.

•

Runoff picks up and carries the loosened soil particles into rivers, lakes, or oceans.

•

It’s the main mechanism of soil erosion and transportation.

+ Why the other choices are incorrect: Answer Choice

Why It’s Incorrect

B. Infiltration

+ Water soaking into the ground does not remove soil; it may reduce erosion by stabilizing soil.

D. Evaporation

+ Water changing from liquid to vapor does not move soil — it’s the opposite (removes water, not soil).

*•' Visual: Water Cycle Elements and Erosion Ç scss Copy Precipitation ↓ (Rain hits soil → loosens it)

Runoff → (Water flows overland → carries soil away)

Infiltration ↘ (Soaks in, helps anchor soil – prevents erosion)

Evaporation ↑ (Removes surface water, has no direct impact on soil movement)

”x3

Real-Life Example:

After a thunderstorm, water rushes across a dirt field, forming gullies and muddy streams.

This is caused by:

•

Precipitation (the rainfall)

•

Runoff (the moving water carrying sediment)

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answers ✓ ⬛ Precipitation and ✓ ⬛ Runoff Main Concept

Rain + moving surface water = soil erosion

Why They’re Right

Precipitation loosens soil; runoff carries it away

Misconception Fixed

Infiltration soaks water into soil (reduces erosion); evaporation removes water, not soil

Water Cycle Cheat Sheet (Hydrologic Cycle) The water cycle is the continuous movement of water through Earth’s atmosphere, surface, and underground. It’s powered by solar energy and gravity.

⬛“ Main Processes to Know Process

What It Is

Example

Evaporation

Liquid water → vapor due to heat (sun)

Puddles drying after rain

Transpiration

Water evaporating from plant leaves

Condensation

Water vapor → liquid water (forms clouds)

Precipitation

Water falling from clouds (rain, snow, sleet, hail)

Rainstorm, snowflakes, hail

Runoff

Water flowing over the land into rivers, lakes, oceans

Floodwater moving downhill

Infiltration

Water soaking into the ground

Rain soaking into soil

Moisture released by forest trees Fog, dew, or cloud formation

Process

What It Is

Example

Groundwater Flow

Underground water moving through rocks/soil Springs, wells to oceans or lakes

Collection

Water gathering in bodies like oceans, lakes, or aquifers

Lakes, oceans, wetlands

Ç* Cycle Sequence Example ' • 1. Evaporation from oceans/lakes 2. Condensation into clouds 3. Precipitation as rain 4. Water either: o

Runs off into rivers (runoff)

o

Or infiltrates into the ground

5. Eventually returns to oceans → cycle repeats

'Cç Quick Mnemonic (To Remember the Core Steps): "Every Cat Pees Really Inconveniently."

(Evaporation, Condensation, Precipitation, Runoff, Infiltration)

^" Bonus Concepts for C165 Term

Why It Matters

Solar energy

Drives evaporation and transpiration

Gravity

Drives runoff, infiltration, precipitation fall

Water conservation Related to understanding how water moves and where it collects Erosion

Caused by precipitation + runoff removing soil

¡ ]#

Surface vs. Atmospheric Processes

Atmospheric Surface Evaporation Runoff Transpiration Infiltration Condensation Groundwater flow Precipitation Collection in rivers/lakes

! Test Tips for C165 •

If soil is washing away → it's precipitation + runoff.

•

If water is absorbed by soil → it's infiltration.

•

If clouds are forming → it’s condensation.

•

If lakes are drying → it's evaporation.

•

Transpiration is always about plants!

O Corrected Question 66 ● Question: Snow falls from the atmosphere and accumulates on a glacier.

Which part of the water cycle does this process represent?

Answer Choices: A. Precipitation B. Infiltration C. Evaporation D. Runoff ⬛Correct Answer: ✓ A. Precipitation

] Topic: □ L Water Cycle Processes (Section 3.2: Earth and Space Systems)

'Cç What is this question testing?

This question tests your ability to: •

Recognize precipitation even when it doesn’t involve liquid rain,

•

Understand how snowfall fits into the water cycle,

•

Distinguish between different water movement pathways (e.g., infiltration vs. runoff vs. accumulation).

✓ Why this answer is correct: ⬛ •

Precipitation is defined as any form of water (liquid or solid) that falls from clouds to Earth’s surface.

•

This includes: o

Rain (liquid)

o

Snow, sleet, hail, freezing rain (solid)

In this question: •

Snow is falling from the atmosphere → this is clearly precipitation.

•

That snow then accumulates on a glacier, which is a long-term storage location (but that’s not the process itself — the falling is what the question is about).

✓ So, the correct label for this part of the water cycle is precipitation. ⬛

+ Why the other choices are incorrect: Answer Choice B. Infiltration

Why It’s Incorrect + This refers to water soaking into the ground — snow on a glacier is not infiltrating.

C. + This is water changing from liquid to gas, usually from surfaces like Evaporation lakes/oceans — not happening here.

Answer Choice

Why It’s Incorrect

D. Runoff

+ Runoff is liquid water moving across land toward rivers — snow sitting on a glacier is not running off.

'Ç

Quick Visual Recap:

text Copy Cloud → ● O Snow → Glacier ↓ This is precipitation

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

✓ ⬛

Precipitation Main Concept

Snow falling from the sky is one type of precipitation

Why It’s Right

Fits definition: water falling from clouds (solid or liquid)

Misconception Fixed

Snow doesn’t count as infiltration, runoff, or evaporation — it’s part of precipitation

ę Corrected Question 67 ' Question: A gardener is working in a garden on a hot, humid day. Suddenly, clouds begin to form.

Within a few hours, gusty winds and a thunderstorm are passing through the area. After the storms pass, the weather is clear and much cooler.

What caused this change in weather?

Answer Choices: A. A high pressure system rested over the area.

B. A low pressure system rested over the area.

C. A cold front moved through the area.

D. A warm front moved through the area. ⬛ ✓ Correct Answer: C. A cold front moved through the area.

□ Topic: ] L Weather Systems s Fronts (Section 3.2: Earth and Space Systems)

C What is this question testing? ç ' This question tests your ability to: •

Identify signs of a cold front,

•

Understand how air masses and fronts influence weather changes,

•

Recognize typical weather progression associated with frontal boundaries.

✓ Why this answer is correct: ⬛ A cold front forms when a cold air mass pushes into a warm, humid air mass. Here's what typically happens: 1. Warm, humid air rises quickly over the advancing cold air.

2. This rapid uplift leads to cloud formation, often cumulonimbus clouds.

3. Results in gusty winds, thunderstorms, and sometimes severe weather.

4. After the cold front passes, the area experiences cooler, drier air and clearing skies.

This exactly matches the scenario in the question: •

Hot, humid conditions → clouds → thunderstorms → cooler, clear air

✓ That pattern = cold front. ⬛

+ Why the other choices are incorrect: Answer Choice Why It’s Incorrect A. High pressure + Brings calm, clear skies, not thunderstorms or gusty winds. Usually system associated with stable, dry weather.

B. Low pressure + Can cause storms, but usually results in longer-lasting cloudiness system and rain, not a quick storm with cooler air behind it.

D. Warm front

+ Brings gentle rain and gradual warming, not intense storms or cool air. Often produces cloudy, drizzly weather.

n Weather Front Summary Table: ↓' Front Type

What It Brings

Example Weather

Cold Front

Fast-moving cold air pushes under warm air

ę Thunderstorms, gusts, cooling '

Warm Front Warm air slides over cooler air

V' Drizzle, gradual warming

High Pressure

• Clear, calm weather +

Sinking, stable air

Low Pressure Rising air, clouds C instability

' Rain, clouds, sometimes C storms

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ A cold front moved through the area

Main Concept

Cold fronts bring thunderstorms and cooler air afterward

Why It’s Right

Matches pattern of humid air → storm → cooler, clear air

Component

Explanation

Misconception Fixed

Thunderstorms are often caused by cold fronts, not warm ones or pressure alone

~ t Question 68 * _ Question: A hiker needs to select a day for a hike. The hiker examines weather forecasts for the next several days.

Which day should the hike be planned for, if the hiker wants to hike on a clear day with no clouds?

Answer Choices: A. A day when a high pressure system rests over the area B. A day when a low pressure system rests over the area C. A day when a warm front moves through D. A day when a cold front moves through ⬛Correct Answer: ✓ A. A day when a high pressure system rests over the area

□ Topic: ] L Weather Systems and Pressure Systems (Section 3.2: Earth and Space Systems)

C What is this question testing? ç ' This question tests your understanding of: •

The relationship between air pressure and weather,

•

How high-pressure systems create different conditions from low-pressure systems,

•

How fronts affect cloud cover and precipitation.

✓ Why this answer is correct: ⬛ •

A high-pressure system is characterized by:

o

Sinking air, which inhibits cloud formation,

o

Dry, stable weather,

o

Often associated with clear skies, light winds, and pleasant outdoor conditions.

✓ This is the best kind of weather for hiking — clear, dry, and stable. ⬛

+ Why the other choices are incorrect: Answer Choice Why It’s Incorrect B. Low pressure system

+ Associated with rising air, clouds, and often rainy or stormy conditions — not ideal for hiking.

C. Warm front

+ Brings increasing cloud cover, light rain or drizzle, and humid air — not reliably clear.

D. Cold front

+ Often brings thunderstorms and then cooler, clearer air — but not during the front’s passage. It can be dangerous to hike when it's moving through.

'•(

Quick Chart: Pressure Systems and Weather

System or Front Weather Conditions

Good for Hiking?

High Pressure Clear skies, calm, dry

⬛ ✓ Yes

Low Pressure

Cloudy, rain, storms

+ No

Warm Front

Overcast, drizzle, gradual warming

+ No

Cold Front

Thunderstorms, gusts, rapid temp drop + No (too unstable)

⬛ Summary Breakdown: ✓

Component

Explanation

Correct Answer

⬛ ✓ A day when a high pressure system rests over the area

Main Concept

High pressure = sinking air = clear skies and calm weather

Why It’s Right

Best conditions for hiking = no clouds, no storms, and stable air

Misconception Fixed

Cold or warm fronts don’t guarantee good weather — they bring change and instability

C Easy Way to Remember: For Low s High Pressure Systems> Think: When you Fly in a ç' Plane. High Pressure System- Clear skies, stable air C weather conditions= good flying conditions. Low Pressure System- Rain, clouds, sometimes storms= poor flying conditions. ●lCorrected Question 6G Question: Which of these is an example of climate change caused by natural variation?

Answer Choices: A. The low rainfall that helped produce the Dust Bowl in the American Great Plains B. The increase in the Sahara Desert’s area from overgrazing by farm animals in North Africa C. The decrease in average humidity of the air from draining swampland in an area D. The decrease of rainfall from cutting down the trees in a rainforest ⬛Correct Answer: ✓ A. The low rainfall that helped produce the Dust Bowl in the American Great Plains

] Topic: L □ Climate Change – Human vs. Natural Causes (Section 3.2: Earth and Space Systems)

ç'C What is this question testing?

This question checks whether you can: •

Differentiate between climate change caused by natural cycles (e.g., ocean currents, volcanic eruptions, droughts)

•

Versus human-caused (anthropogenic) climate changes (e.g., deforestation, urbanization, pollution)

✓ Why this answer is correct: ⬛ •

The Dust Bowl of the 1930s involved a naturally occurring drought — a prolonged period of low rainfall in the U.S. Great Plains.

•

Although farming practices worsened the impact, the drought itself was a natural climate variation — part of Earth’s long-term fluctuations in rainfall and temperature patterns.

⬛ So, Answer A is an example of climate change caused by natural variation. ✓

+ Why the other answer choices are incorrect: Answer Choice

Why It’s Incorrect

B. Overgrazing in the + This is a human-caused (anthropogenic) change — Sahara overgrazing strips vegetation, causing desertification.

C. Draining swampland

+ Draining wetlands is human activity, which affects humidity and local climate.

D. Cutting down rainforest trees

+ Deforestation reduces rainfall and increases carbon in the atmosphere — a major human-driven cause of climate change.

?● Human vs. Natural Climate Change Examples: Natural Causes

Human (Anthropogenic) Causes

Volcanic eruptions

Deforestation

Natural droughts

Burning fossil fuels

Earth’s orbit shifts (Milankovitch cycles) Urbanization (heat islands) Ocean current changes (like El Niño)

Agriculture (methane, land changes)

✓ Summary Breakdown: ⬛ Component

Explanation

Correct Answer

⬛ ✓ A. The low rainfall that helped produce the Dust Bowl

Main Concept

Recognizing that not all climate change is human-caused

Why It’s Right

The rainfall drop was a natural drought, not triggered by human behavior

Misconception Fixed

Human activity made the Dust Bowl worse, but the initial cause was natural

5„) NATURAL CAUSES OF CLIMATE CHANGE These occur without human influence, and have shaped Earth's climate over millions of years.

Cause Volcanic Eruptions Solar Variation Earth’s Orbital Changes

How It Affects Climate

Example

Emit ash and gases → cooling from

Mt. Pinatubo eruption (1991)

sunlight blockage Changes in sun’s energy output → warming or cooling Milankovitch cycles change how sunlight hits Earth

Natural Droughts or Wet Normal fluctuation in precipitation Periods patterns

Sunspot cycles Triggered past ice ages Dust Bowl drought (1930s)

Ocean Current Changes

Events like El Niño/La Niña shift global rainfall/temps

El Niño warms, La Niña cools

Tectonic Activity

Affects ocean currents C atmospheric circulation

Uplift of mountain ranges

C Tip to remember: ' ç

Natural causes = “VOTES” Volcanoes, Orbital shifts, Tectonics, El Niño, Solar changes

¡˜ ANTHROPOGENIC (HUMAN) CAUSES OF CLIMATE CHANGE …

These are caused by human behavior and have rapidly increased since the Industrial Revolution.

Cause Burning Fossil Fuels Deforestation

How It Affects Climate

Example

Releases CO₂, trapping heat → global

Coal power plants, car emissions

warming Removes trees that absorb CO₂ → increases greenhouse gases

Industrial Emissions Factories release greenhouse gases

Agriculture Urbanization (Heat Islands) ç' C

Livestock release methane; fertilizers

Amazon rainforest logging Cement, steel, and chemical plants

release nitrous oxide

Cattle farms, overuse of fertilizer

Cities absorb heat and reduce vegetation

Big cities are warmer than rural areas

Tip to remember:

Human causes = “BAD AIR” Burning fuels, Agriculture, Deforestation, Air pollution, Industry, Reflectivity loss

⬛ Natural vs. Human Comparison Chart “ Factor

Natural

Human

Source

Earth/sun processes

Human activity

Timescale

Over millennia

Mainly past 200 years

Speed of Change

Gradual

Rapid

Factor

Natural

Example Effect

Ice ages, volcanic winters

Human Rising global temps, melting glaciers

↓n' Exam Tip: •

If the change is gradual or linked to volcanoes, solar cycles, or drought → it's NATURAL.

•

If the change involves industry, deforestation, or greenhouse gases → it's HUMAN-CAUSED.

↓ Question 70 n' Question: What is an example of climate change that can be caused by human activity?

Answer Choices: A. Changes in average temperature from increases in atmospheric carbon dioxide B. Changes in average temperature from changes in the sun’s energy emission C. Changes in average temperature over Earth’s history from changes in Earth’s tilt D. Changes in temperature from the onset of the last ice age ⬛Correct Answer: ✓ A. Changes in average temperature from increases in atmospheric carbon dioxide

] Topic: □ L Climate Change – Human Causes (Section 3.2: Earth and Space Systems)

Cç What is this question testing? ' This question tests whether you can: •

Identify anthropogenic (human-caused) climate change,

•

Differentiate it from natural variations in Earth’s climate,

•

Recognize the role of greenhouse gases like CO₂ in warming the planet.

✓ Why this answer is correct: ⬛ •

Carbon dioxide (CO₂) is a greenhouse gas.

•

Human activities — especially burning fossil fuels, deforestation, and industrial processes — significantly increase CO₂ levels in the atmosphere.

•

This leads to enhanced greenhouse effect → global warming → climate change.

⬛ Therefore, A is the best example of climate change caused by human activity. ✓

+ Why the other answer choices are incorrect: Answer Choice

Why It’s Incorrect

B. Sun’s energy emission

+ That’s a natural cause — variations in solar output affect Earth’s temperature cycles but aren’t driven by humans.

C. Earth’s tilt

+ Another natural cause — orbital changes (Milankovitch cycles) explain ice ages and warm periods in Earth’s distant past.

D. Onset of the last ice age

+ Completely natural — occurred due to Earth’s axial tilt and orbital patterns, not human activity.

˜ ¡…

Quick Recap: Human-Caused Climate Change

Human Activity

Effect

Burning fossil fuels Adds CO₂ → traps more heat Deforestation

Fewer trees to absorb CO₂

Agriculture

Releases methane and nitrous oxide

Industrial emissions Contribute more greenhouse gases

✓ Summary Breakdown: ⬛

Component

Explanation

Correct Answer

⬛ ✓ Changes in temperature due to increased atmospheric CO₂

Main Concept

Greenhouse gases from human activity trap heat → global warming

Why It’s Right

Matches current scientific consensus on human-driven climate change

Misconception Fixed

Natural causes (like ice ages, Earth’s orbit, sun) aren’t the result of human activity

Y Ç

Question 71:

Q: Where are most of the asteroids in the solar system located?

A: ✓ ⬛ Between Mars and Jupiter

□ Topic: ] L Solar System Structure – Asteroid Belt (Section 3: Earth and Space Systems)

C What the Question Is Testing: ç ' This question tests your knowledge of the layout of the solar system, particularly the location of the asteroid belt, which separates the inner (terrestrial) and outer (gas giant) planets.

⬛ Why This Is the Correct Answer: ✓ •

The asteroid belt is a region filled with rocky debris and minor planets.

•

It is located between Mars and Jupiter.

•

It marks the boundary between the rocky inner planets and the gaseous outer planets.

+ Why the Other Choices Are Incorrect:

Option

Why Incorrect

Between the Sun and That area is too close to the Sun and largely empty aside from Mercury solar radiation.

Between Earth and Mars

No major asteroid belt there — planets are too close together.

Between Saturn and Uranus

That’s part of the outer solar system — contains gas giants and some moons, not the asteroid belt.

c Memory Tip: ) ’ F “Mars to Jupiter = Belt of Boulders” S’ The Asteroid Belt sits like a border patrol between the rocky and gassy planets!

Topic Summaries for Questions not included that appeared on the PA C OA Terrestrial vs. Gas Planets – Quick Recap

●Ç ?

Y

🪨 Terrestrial Planets Definition: Small, rocky planets with solid surfaces.

Planets Included: •

Mercury

•

Venus

•

Earth

•

Mars

˙ ( ( Key Features: Feature

Description

Surface

Solid, rocky crust

Feature

Description

Size

Smaller

Mass

Lower than gas giants

Density

Higher

Moons

Few or none

Rings

None

Atmosphere Thin or moderate (varies by planet) Core

Dense metallic core

Location

Closer to the sun (inner solar system)

V' Gas Giants (Jovian Planets) Definition: Large planets made mostly of gases with no solid surface.

Planets Included: •

Jupiter

•

Saturn

•

Uranus

•

Neptune

˙ ( Key Features: Feature

Description

Surface

No solid surface (mostly gas)

Size

Much larger

Mass

Much greater than terrestrial planets

Density

Lower (less compact)

Feature

Description

Moons

Many (dozens or more)

Rings

All have rings (Saturn’s are most visible)

Atmosphere Thick atmospheres of hydrogen, helium, and other gases Core

Possibly small rocky or metallic core

Location

Farther from the sun (outer solar system)

★ What Do All Planets Have in Common? ✓ Orbit the Sun ⬛ ⬛ Are spherical in shape (due to gravity) ✓ ✓ Have cleared their orbit of debris ⬛ ⬛ Have mass and gravity ✓ ⬛ Can have moons ✓ ✓ Are part of our solar system's layout (inner vs outer planets) ⬛

'çC

Memory Tips:

J "My Very Educated Mother Just Served Us Nachos" ● Terrestrial: Mercury, Venus, Earth, Mars ?

V' Gas Giants: Jupiter, Saturn, Uranus, Neptune ·+F’ • S C165 Solar System Recap – What You Should Know

? 1. Order of the Planets ● Use this memory trick: ç'C “My Very Educated Mother Just Served Us Nachos” •

Mercury

•

Venus

•

Earth

•

Mars

•

Jupiter

•

Saturn

•

Uranus

•

Neptune

🪨 2. Types of Planets Type

Planets

Terrestrial Gas Giants

Key Features

Mercury, Venus, Earth, Mars Jupiter, Saturn

Ice Giants Uranus, Neptune

Rocky, small, dense, solid surfaces, few or no moons Huge, made mostly of hydrogen/helium, many moons, rings Smaller than gas giants, icy cores, methane gives them color

Ç 3. Key Regions of the Solar System ○ Region

What's There

Asteroid Belt

Between Mars and Jupiter, full of rocky asteroids

Kuiper Belt

Beyond Neptune, icy bodies (e.g., Pluto, Eris)

Oort Cloud (theory) Distant shell of icy objects — possible source of comets

● 4. Moons and Rings •

Earth has 1 moon.

•

Mars has 2 small moons (Phobos C Deimos).

•

Jupiter and Saturn have dozens of moons each — e.g., Jupiter's Ganymede (largest moon).

•

Saturn has the most visible rings, but all gas/ice giants have rings.

• 5. The Sun + •

The Sun is a medium-sized star (yellow dwarf).

•

It makes up GG.8% of the mass in the solar system.

•

Produces energy through nuclear fusion (hydrogen into helium).

SF 6. Other Celestial Bodies ’ Object

What to Know

Asteroids

Rocky, irregular bodies, mostly in asteroid belt

Comets

Icy bodies with tails when near the Sun (from Kuiper Belt or Oort Cloud)

Meteoroids

Small rock/metal in space

Meteors

Meteoroids that burn in Earth's atmosphere ("shooting stars")

Meteorites

Meteors that land on Earth

Dwarf planets Pluto, Eris, Ceres — orbit Sun but haven’t cleared their orbit

“ 7. Gravity ⬛

†ˇ`

•

Gravity holds the solar system together.

•

The Sun’s gravity keeps planets in orbit.

•

Larger mass = stronger gravity.

8. Orbits and Rotation

Term

Definition

Orbit

The path a planet takes around the Sun (elliptical)

Rotation A planet spinning on its axis (causes day/night) Revolution One full orbit around the Sun (1 year)

Ç' G. Tilt s Seasons • *

'çC

•

Earth is tilted 23.5° on its axis.

•

This tilt + orbit causes seasons (not distance from the Sun).

•

More direct sunlight = summer, less direct = winter.

Memory Boosters: •

"Inner planets are rock solid, outer ones are gas-filled."

•

Jupiter = biggest, Mercury = smallest

•

Saturn = rings, Neptune = winds, Uranus = rotates sideways

•

Pluto is a dwarf planet because it hasn’t cleared its orbit.

J[ s3/ySound Waves vs. Electromagnetic Waves – Quick Recap • Feature ¸? Ç

J Sound Waves

/3syElectromagnetic (EM) Waves [

Type of wave

Mechanical wave

Electromagnetic wave

Requires a medium?

✓ Yes – needs a material (air, ⬛

Speed

Slower (343 m/s in air)

Faster (300,000,000 m/s in vacuum)

+ No

⬛ ✓ Yes

water, solid)

Can travel through vacuum?

Examples

Voice, music, earthquake waves

+ No – travels through vacuum

Light, radio waves, X-rays, microwaves

?

• Ç ¸ Feature

J Sound Waves

y/s3[ Electromagnetic (EM) Waves

Wave type (motion)

Longitudinal (vibrates parallel to Transverse (vibrates perpendicular to motion) motion)

Detected by

Ears, microphones

Affected by medium?

⬛ ✓ Yes – speed and clarity change in solids, liquids, gases

⬛ Yes – can bend (refract), reflect, ✓ or be absorbed by materials

Produced by

Vibrating objects

Vibrating electric and magnetic fields

Eyes (for visible light), antennas, sensors

C' Memory Tips: ç •

"Sound needs stuff, light does not." (Sound needs a medium; light doesn’t)

•

Sound = slower, EM = faster

•

Sound = longitudinal, EM = transverse

J Examples of Sound Waves (Mechanical): •

Echo in a canyon

•

A speaker vibrating air

•

Seismic waves (some types)

/3sy[ Examples of Electromagnetic Waves: Type

Use Example

Radio

Phones, radios

Microwaves Microwave ovens, radar Infrared

Night vision, remote controls

Visible light What we see

Type

Use Example

Ultraviolet Sunburns, sterilization X- rays

Medical imaging

Gamma rays Cancer treatment, nuclear reactions ˛ ● fµ O Phase Changes: Endothermic vs. Exothermic

↓n What Is a Phase Change? ' A phase change is when a substance changes from one state of matter to another (solid ↔ liquid ↔ gas). These changes happen when thermal energy (heat) is added or removed.

+ Endothermic Changes (Energy is absorbed from the surroundings) Phase Change

Direction

Example

Melting

Solid → Liquid Ice cube melts in your hand

Boiling / Evaporation Liquid → Gas Water boils into steam Solid → Gas

Sublimation ' çC

Dry ice turns into carbon dioxide gas

Memory Tip:

"Endo = In" → Energy goes in (absorbed) The substance gets hotter

— Exothermic Changes (Energy is released to the surroundings) Phase Change Direction Freezing

Example

Liquid → Solid Water freezes into ice

Phase Change Direction

Example

Condensation Gas → Liquid Steam condenses on cold mirror Deposition ç 'C

Gas → Solid

Frost forming on a window

Memory Tip:

"Exo = Exit" → Energy exits (released) The substance gets cooler

⬛“ Summary Chart Change

Phase

Endo/Exo?

Melting

Solid → Liquid ✓ ⬛ Endothermic

Freezing

Liquid → Solid ⬛ ✓ Exothermic

Boiling

Liquid → Gas

⬛ Endothermic ✓

Condensation Gas → Liquid

✓ ⬛ Exothermic

Sublimation Solid → Gas

⬛ ✓ Endothermic

Deposition

⬛ ✓ Exothermic

Gas → Solid

ị On the C165 Test: You may see phrasing like: “Which phase change absorbs energy?” → Answer: Melting, Boiling, or Sublimation “Which phase change releases energy?” → Answer: Freezing, Condensation, or Deposition ➊ Types of Chemical Bonds – Quick Recap 3 S

1. ) f Ionic Bonds

Definition: Electrons are transferred from one atom to another.

Feature

Description

Occurs Between

Metal + Nonmetal

Electrons

Transferred from metal → nonmetal

Bond Strength

Strong

State at Room Temp Usually solid (crystalline structure) Conductivity

Conducts electricity when dissolved in water

Example

NaCl (table salt), MgO

ç 'C

Memory Tip:

Ionic = I Owe You Electrons!

2. :!ć fi Covalent Bonds Definition: Electrons are shared between atoms.

Feature

Description

Occurs Between

Two nonmetals

Electrons

Shared (1 or more pairs)

Bond Strength

Varies (can be strong or weak)

State at Room Temp Often liquid or gas Conductivity

Does not conduct electricity

Example

H₂O (water), CO₂, CH₄ (methane)

C' Memory Tip: ç Covalent = Co-owning Electrons!

3. †=: Metallic Bonds

Definition: Metal atoms share a “sea” of electrons freely.

Feature

Description

Occurs Between

Metals only

Electrons

Free-floating in a “sea”

Bond Strength

Strong and flexible

State at Room Temp Solid (except mercury) Conductivity

Excellent conductor of heat and electricity

Example

Fe (iron), Cu (copper), Al (aluminum)

ç Memory Tip: 'C Metallic = Mobile electrons in a metal mob!

Y

Quick Comparison Chart

Bond Type Who’s Involved

Electrons

Conductivity

Example

Metal + Nonmetal

Transferred

Yes (in water)

NaCl (salt)

No

H₂O, CO₂

Ionic

Covalent Nonmetal + Nonmetal Shared Metallic

Metal + Metal

Free-floating “sea” Yes (solid metals) Cu, Fe

† How to Recognize Them on the Test: n_•.

•

Metal + Nonmetal? → Ionic

•

Nonmetal + Nonmetal? → Covalent

•

Just Metals? → Metallic

⬛ Ions and Forces Between Them – Recap

ç̆⬛l What Is an Ion?

An ion is an atom (or molecule) that has gained or lost electrons, giving it an electric charge.

Type of Ion How It Forms

Charge

Example

Cation

Loses electrons (usually a metal) Positive (+) Na⁺, Ca²⁺

Anion

Gains electrons (usually a nonmetal) Negative (−) Cl⁻, O²⁻

C Memory Tip: ç ' •

Cation = Cat has paws = Pawsitive

•

Anion = Think “a negative ion”

)f What Holds Ions Together? (Ionic Bonds) •

Opposite charges attract.

That electrostatic force pulls cations and anions together.

This forms ionic compounds like NaCl (table salt).

! Clarifying the Term: “Nuclear Force Between Ions” This phrase may appear on tests or in textbooks, but it's often confusing. ● Misconception Alert: •

Nuclear forces = forces inside the nucleus (between protons C neutrons).

•

But ions are atoms that have lost/gained electrons — that’s outside the nucleus.

⬛ So what’s actually meant in context? ✓ They likely mean electrostatic (Coulombic) forces between ions, not nuclear forces.

Force

Where it Acts

Electrostatic Force

Between positive and negative charges

Nuclear Force

Inside the atomic nucleus

Relevant to Ions? ⬛ ✓ Yes

Example Na⁺ attracted to Cl⁻

+ No (not between Holds nucleus together ions)

"^ Example: Sodium Chloride (NaCl) 1. Sodium (Na) loses 1 electron → becomes Na⁺ (cation) 2. Chlorine (Cl) gains 1 electron → becomes Cl⁻ (anion) 3. Na⁺ and Cl⁻ are attracted by electrostatic forces 4. They form a solid ionic crystal held together by strong ionic bonds

5. . n Summary Cheat Sheet • _ † Term

Definition Ion Atom with a net charge (gained or lost electrons) Cation Positively charged ion (lost electrons) Anion Negatively charged ion (gained electrons) Ionic bond Electrostatic attraction between oppositely charged ions Nuclear force Strong force inside nucleus – not related to ions Electrostatic force The real force between ions – causes ionic bonding )+ E Σ: ⯍x Elastic vs. Inelastic Collisions – Quick Recap X

⬛“ What’s a Collision?

A collision happens when two objects hit each other and interact through forces. After the collision, they may bounce off, stick together, or deform.

The two key types of collisions are: Elastic Collision

Inelastic Collision

Definition

Objects bounce off each other

Objects stick together or deform

Kinetic Energy

Conserved (no loss)

Momentum

⬛ ✓ Conserved

Not conserved (some lost as heat, sound) ⬛ ✓ Conserved

Real-World Example

Elastic Collision

Inelastic Collision

Billiard balls colliding

A car crash where cars crumple and stick

⬛ What’s Conserved in Each Type?

Type of Collision Momentum Kinetic Energy Elastic

✓ ⬛ Yes

⬛ ✓ Yes

Inelastic

⬛ ✓ Yes

+ No (some lost)

ị Inelastic Collisions on the Test The most common inelastic collision example you'll see is: “Two objects collide and stick together.” → That’s inelastic because kinetic energy is lost, but momentum is still conserved.

'çC

Memory Tips •

Elastic = Energy is conserved (Think: rubber balls bounce off each other cleanly)

•

Inelastic = Involves Impact s Sticking (Think: a car crash = kinetic energy lost)

" Example: ^ Two balls of equal mass collide head-on: Situation

Type

They bounce off each other without deforming Elastic They stick together and move as one object

Inelastic

’,‘˙)f Key Takeaways for C165: •

✓ Momentum is always conserved in both types. ⬛

•

+ Kinetic energy is only conserved in elastic collisions.

•

Sticky = inelastic, bouncy = elastic

🪨 Rock Layers Recap (Stratigraphy s Geologic History)

< ] ‘ˇ ‹ , 1. Law of Superposition

ç' C

•

In undisturbed rock layers, the oldest layers are at the bottom, and the youngest are at the top.

•

Think of it like a layered cake: the bottom layer was put down first.

Memory Tip:

“Oldest on bottom, youngest on top”

{~

2. Types of Rock Layers

Rock Type

How It Forms

Clues It Tells

Sedimentary

Layers of sediment compacted over time

Often contains fossils; forms in water

Igneous

Cooled lava or magma

Formed from volcanic activity

Metamorphic Rocks changed by heat and pressure Shows deformation or deep burial

🪨 3. Intrusions s Unconformities •

Intrusion: Magma that cuts through rock layers and hardens. ➤ It’s younger than the layers it cuts through.

•

Faults: Cracks where movement has occurred. ➤ Faults are younger than the layers they break.

•

Unconformity: Missing time in the record (erosion or lack of deposition). ➤ Suggests that something disrupted the normal layering.

γ Ç

4. Fossils in Layers •

Index Fossils: Fossils used to date layers based on species known to exist during a specific time range.

•

Deeper fossils = older life forms

•

Fossils tell us past environments (e.g., marine fossils = ocean used to be there)

ç 5. What You Can Learn from Layers ' C Clue

What It Tells You

Layer order

Age sequence (oldest → youngest)

Rock type

Environment (e.g., water, heat, volcano)

Fossils

Time period C life forms

Intrusions/faults Events after layer deposition Changes in texture Pressure, heat, or erosion

’ Example: ‘ µ Layer

Rock Type

Meaning

A (Top)

Limestone

Shallow sea (marine fossils)

B

Shale

Muddy water environment

C

Sandstone

Desert or beach (sand dunes)

D

Granite (intrusion) Magma forced through → younger than C

E (Bottom) Marble

Was once limestone → changed by heat/pressure

f Key Rules to Remember: ’,‘˙) •

Superposition → older rocks at the bottom

•

Cross-cutting → faults/intrusions are younger than what they cut

•

Original horizontality → layers were deposited flat

•

Fossils → help correlate layers and estimate time

i¸ç f Landforms – Quick Recap ˛ »

◯ ◯● What Are Landforms? · ? ‘ Landforms are natural features of Earth’s surface that are shaped by geological processes like erosion, deposition, uplift, and volcanic activity.

🪨 Major Types of Landforms and How They Form Landform Formed By

Key Features / Notes

Mountains Tectonic uplift, collisions

High elevation, folded or faulted rock

Valleys

Erosion by rivers or glaciers

Low areas between hills/mountains

Plateaus Uplifted flat land, sometimes volcanic Elevated flat regions Plains

Deposition over time

Flat, fertile, low-lying areas

Hills

Erosion-resistant rock or small uplift

Elevated but smaller than mountains

Volcanoes

Eruption of magma from below Earth’s Cone-shaped, located at plate crust boundaries

Dunes

Wind deposition of sand

Glaciers

Compacted snow and ice

Deltas

Deposition at river mouths

Canyons River erosion over long time periods

Found in deserts and beaches Move slowly, shape valleys and carve land Fan-shaped sediment formations Deep valleys with steep sides

Landform Formed By Islands

Volcanic activity, tectonics, or coral

Key Features / Notes Surrounded by water

Meanders Erosion and deposition in river curves Winding bends in rivers

◆+ Landform Processes to Remember L * Process

Creates / Changes

Examples

Erosion

Removes soil/rock by wind, water, or ice Valleys, canyons, cliffs

Deposition Drops sediment in new location

Deltas, beaches, floodplains

Tectonics Uplift, folding, faulting

Mountains, earthquakes, rift valleys

Volcanism Builds land with lava and ash

Volcanoes, islands

Glaciation Carves and shapes land by ice

U-shaped valleys, moraines

Weathering Breaks down rock at surface

Soil formation, rock disintegration

'ç Memory Tips C •

Deposition → Deltas, Dunes

•

Erosion → Excavates (removes) → valleys, canyons

•

Volcano = Constructive, Erosion = Destructive

•

Glaciers carve U-shaped valleys, rivers carve V-shaped valleys

†• Examples You Should Know: _n.

Feature

Location Example

Type

Grand Canyon

Carved by river erosion

Canyon

Himalayas

Formed by tectonic collision

Mountains

Feature

Location Example

Type

Mississippi Delta Formed by sediment deposition Delta Great Plains

Flat area formed by deposition Plain

Mount St. Helens Formed by volcanic activity Volcano »Renewable Energy Sources – Recap ⬛

)f What Is Renewable Energy?

Renewable energy comes from sources that are naturally replenished on a human timescale — meaning they won't run out (unlike fossil fuels).

•-·Major Renewable Energy Sources + Source Solar Energy Wind Energy Hydroelectric

Geothermal Biomass

How It Works

Key Facts

Converts sunlight into electricity

Abundant, clean, weatherdependent

(solar panels) Wind turns turbines to generate electricity

Clean, land-efficient, depends on wind

Moving water spins turbines in dams Most widely used renewable, needs or rivers water Heat from Earth’s interior creates steam Burning organic material for fuel or heat

⬛“ Summary Chart

Reliable, location-limited (hot spots) Renewable but can produce some emissions

Energy Type Replenishes? Pollution?

Limitations

Solar

+ Yes •

None (during use)

Needs sunlight; not 24/7

Wind

-̂ Yes }

None (during use)

Needs consistent wind; noisy

Hydro

Yes

Minimal

Can affect ecosystems, needs rivers

None

Needs tectonic/volcanic activity area

Geothermal ? ● Yes Biomass

” Yes x 3

Some (when burned) Can compete with food crops

_ Helpful Terms: † n.

• •

Steam turbines: Used in geothermal, biomass, and hydroelectric to generate power.

•

Photovoltaic cells: Found in solar panels; convert sunlight to electricity.

•

Turbines: A rotating device used in wind and hydro power.

?T Test Clue: How do they ask this?

“Which renewable energy source produces electricity through steam production?” ✓ Answer: Geothermal or Biomass (sometimes Hydro) ⬛ “Which energy source depends on weather conditions?” ✓ Answer: Wind or Solar ⬛

ç' C

Memory Tips •

“Sun + Wind = Clean but needs weather”

•

“Water (hydro) + Earth (geo) = Steam power”

•

“Biomass = Burn stuff that grows”