Issuu on Google+

1.0 MAGIC SCIENCE

Objectives 1. To attract students’ interest in learning science. 2. To encourage teachers to practice ‘hands-on’ activities in their teaching and learning process.

Rationale 1. To relate certain learning outcomes to daily life. 2. To make teaching and learning process more fun. 3. To enhance students’ understanding of science concepts.

Strategy 1. The teacher can apply this method, ‘Magic in Science’ in any of their lesson either at the beginning or at the end of the lesson.

Notes 1. These activities are just a few examples only. 2. Teachers are encouraged to use other means or strategies to enhance a meaningful and interesting lesson.

1


1.1 WATER AND SOLUTION 1.1.1 WEATHER INDICATING FLOWER Curriculum Specifications Link • • •

Theme : Matter in Nature Learning area : Water and Solution Learning outcomes: Describe the physical characteristics of water – to indicate the presence of water

Introduction This activity is to indicate the humidity of air. The weather-indicating flower can be used to detect the changes in the humidity of the air . The weather changes will be shown by the colour change of cobalt chloride (the petals of the flowers). Materials • Cobalt chloride (about 20g) • Blotting paper/ filter paper • Cotton thread • Flower stick (about 15cm) • Scissors • Sewing needle • Button • Leaf • Hair -drier • Water sprinkler • Modeling clay/ plasticine • A clay pot What Do I Do?

2


1. 2. 3. 4.

A small sheet of blotting paper/ filter paper is cut into the shape of a flower. Then, the flower is tied with cotton thread to the thick wire. Add about 20g of cobalt chloride into a bowl of water to form a strong solution. The blotting paper flower is dipped in this solution and dried using a hair – drier. 5. The weather-indicating flower is placed in a pot which filled with modeling clay/ plasticine to hold it. 6. The weather-indicating flower is ready. Hair -drier is used to create the condition of dry weather and water sprinkler is used to sprinkle water as rain. 7. If the colour of the flower turns pink, it indicates the humidity is high and if the colour remains blue, it indicates is low or dry weather. What is Happening? The cobalt chloride can be used as an indicator to detect the presence of water and water vapour by changing the colour of cobalt chloride from blue to pink. So, the changes in colour of the flower indicates the presence of water vapour in the air. •

It is interesting and can attract the attention of the students. Suitable to use as an activity for science society, science week and programme after PMR.

3


1.1.2

MAGIC SOLUTION

Curriculum Specifications Link • • •

Theme : Matter in Nature Learning area :Water and Solution Learning outcomes: Identifying the properties of acid and alkali

Wiped with alkali

Wiped with acid

Beaker A

Beaker B

Magic solution (Phenolphthalein solution)

Beaker C

Introduction This activity is to introduce one of the properties of acid and alkali which can change the colour of Phenolphthalein solution. Phenolphthalein solution can be used as an indicator to indicate the presence of acid or alkali.* Name of indicator Phenolphthalein (colourless)

Colour in acid colourless

Materials and Apparatus • 2 beakers (100ml) • 1 beaker (250ml) • Acid • Alkali • Cotton • Forceps • Phenolphthalein solution

What Do I Do? 4

Colour in alkali pink


1.

Using cotton, wipe the inner surface of each 100ml beaker with acid and alkali respectively (use forceps to hold the cotton). 2. Leave both beakers to dry. 3. Fill the 250ml beaker with magic solution (Phenolphthalein solution). 4. Ask two students to hold each beaker. 5. Ask a question to both students. Example: • Is there anything inside the beaker? • Is the beaker clean? 6. Tell the students that the magic solution can show whether the student are correct or not. 7. If the colour of the magic solution changes – the student that hold the beaker is wrong. 8. Then, teacher pour the colourless magic solution into each beaker (50ml). 9. All the students are asked to observe the changes occur. 10. Then teacher explains what actually happen.

What is Happening? When the magic solution (Phenolphthalein) is poured into the beaker which is wiped with acid, it does not changed colour but when it is poured into a beaker which is wiped with alkali, the solution turns pink. •

1.2

This activity is suitable for set induction to introduce acid and alkali.

AIR PRESSURE 5


1.2.1

AMAZING GLASS

Curriculum Specifications Link • • •

Theme : Technological and Industrial Development in Society Learning area : Air pressure Learning outcomes : Explain the existence of air pressure with reference to the Kinetic Theory,

Introduction •

This activity shows how a glass full of water being held upside down without losing a drop of water.

Materials and Apparatus •

a glass, cardboard/hard plastic sheet, water

What Do I Do? 1. Fill a glass full with water. 2. Place a piece of cardboard/hard plastic sheet on top of the glass. 3. Invert the glass and see what happened.

What is Happening? The cardboard/hard plastic sheet does not fall in spite of the weight (force) of water pushing it downwards. This shows that there is a greater force which acts upward, to support the cardboard/hard plastic sheet. Note : The air pressure exerted on the card is strong enough to support the weight of the water in the glass.

1.2.2

MOVE A COIN ON A BOTTLE 6


Curriculum Specifications Link • • •

Theme : Technological and Industrial Development in Society Learning area : Air pressure Learning outcomes : Explain the factors affecting air pressure.

Introduction •

This activity shows that the heat from our body can be used to increase the air temperature inside the bottle. Thus, it moves the coin.

Materials and Apparatus • A coin, a glass bottle What Do I Do? 1. 2. 3. 4. 5.

Wipe the mouth of the glass bottle with water. Place the coin on the mouth of the bottle. Rub both palms until they becomes warm. Hold the bottle immediately with both hands. Observe what happens to the coin.

What is Happening? The heat from the hands increased the temperature of air inside the bottle that causes the coin to jump up. • Comment: Teacher can also use ping-pong ball instead of coin.

1.3 DYNAMIC 1.3.1 REMOTE CONTROL ROLLER 7


Curriculum Specifications Link • • •

Theme : Force and Motion Learning area : Dynamics Learning outcomes : (i) State that a force is a push or a pull (ii) Explain the effects of forces

Introduction This activity shows that once you’ve rubbed the balloon on your hair, it will attract other things towards it. Apart from balloon, other materials like comb, plastic ruler, plastic bottle can also be used. Materials •

Empty soda can, blown up balloon, your hair

What Do I Do? 1. Put the can on its side on a table or the floor (any place that is flat and smooth). Hold it with your finger until it stays still. 2. Rub the balloon back and forth on your hair really fast.(we can used other material to produce electrostatic force such as cotton wool,silk) 3. Hold the balloon about 2 to 3 cm in front of the can. The can will start to roll, even though you are not touching it.

8


4. Move the balloon away from the can slowly and the can will follow the balloon. 5. If you move the balloon to the other side of the can, the can will roll in the other direction. 6. How fast will the can roll? How far can you roll it before the can stops? Will it roll uphill? 7. If you have some friends with cans and balloons you can have a race across the room or down the side walk.

What is Happening? When you rub a balloon on your hair, it ends up loaded with electrons (negative charges). These electrons attract: 1. the protons (positive charges) in the soda can, 2. the protons (positive charges) in a trickle of water, 3. the protons (positive charges) in your hair This shows that there is electrostatic force.

9


1.3.2

SPIDER SLIDER

Curriculum Specifications Link • • •

Theme : Force and Motion Learning area : Dynamics Learning outcomes : Explain the effects of forces (frictional force)

Cardboard Toothpick

1 toothpick long Folded part

2 toothpick long Blue tacks/ plasticine

(i) Cut out a piece of cardboard into a strip as shown above

(ii) Press the toothpick on to the blue tack/ plasticine across the middle of the strip. Fold up a small piece (about 5mm) at both ends of the strip.

Thread

Needle

(iii)

Glue the card onto the back of the spider

(iv) By using a needle, thread through the middle of each fold of the strip

10


(v)

Hold the thread tight between your hands, with one hand above the other. Then let the thread go slack. Observe what happens.

Introduction This activity shows that when an object moves across a surface, it is slowed down as the two surfaces rub against each other. This force is called friction. Some surfaces have more friction than others. Materials •

Cardboard, scissors, cotton thread (half metre), needle, toothpick, glue, blue tack/ plasticine, coloured paper and pencil colours.

What Do I Do? 1. Cut out a piece of cardboard into a strip as shown in the diagram in (i). 2. Press the toothpick on to the blue tack/ plasticine across the middle of the strip. 3. Fold up a small piece at both ends of the strip. 4. Draw a spider shape on a coloured paper. Make sure the spider is bigger than the strip. 5. Cut out the spider shape. 6. Draw eyes and fangs using pencil colours. 7. Glue the strip onto the back of the spider. 8. By using a needle, thread through the middle of each fold of the strip. 9. Hold the thread tightly between your hands, with one hand above the other. Then let the thread go loosely. 10. Observe what happens.

11


What is Happening? When the thread is held taut, it touches the toothpick. This causes friction between the toothpick and the thread. This is strong enough to stop the spider from moving down the thread. But, when you let the thread go slack, it no longer touches the toothpick. This means there is less friction, so the spider slides down easily. • • •

It is interesting and can attract the attention of the students The model must be prepared before teaching and learning process Suitable to use as an activity for science society

12


1.4

STABILITY 1.4.1 CENTRE OF GRAVITY

Curriculum Specifications Link • • •

Theme : Technological and Industrial Development in Society Learning area : Stability Learning outcomes: Determine the point of equilibrium in regular and irregular shapes.

Introduction •

This activity is to determine the point of equilibrium in regular and irregular shapes.

Materials and Apparatus • Walking stick/ meter rule/ pencil What Do I Do? 1. Hold the walking stick at both ends with hands such in the picture above. 2. Slowly, move your right hand towards the left hand until they meet. 3. The point where both hands meet is the centre of gravity of the walking stick. 4. Put the walking stick on your palm at the centre of gravity What is Happening? When the right hand is moved towards the left hand, the walking stick will be balanced automatically on both hands at its centre of gravity.Once the centre of gravity is located, we can balance the walking stick on our palm.(Refer to 2 nd picture) •

It is interesting and can attract the attention of the students

13


1.4.2

“AYER ROCK”

Irregular shape rock

Flat surface Curriculum Specifications Link • • •

Theme : Technological and Industrial Development in Society Learning area : Stability Learning outcomes : Relate the centre of gravity to the stability of objects.

Introduction •

This activity is to relate the centre of gravity of the irregular rock to its stability.

Materials and Apparatus • Irregular shape of rock What Do I Do? 1. Stand the irregular shape rock with the bigger surface area at the bottom. 2. Try to balance it on a flat surface till it stays upright without any support. 3. Student explains the observation. What is Happening? When the bigger base area of the rock is placed at the bottom, this will lower its centre of gravity. So the rock will achieve stability and could stay upright for a longer period

14


1.4.3

“VEGGIE-HANG”

Curriculum Specifications Link • • •

Theme : Technological and Industrial Development in Society Learning area : Stability Learning outcomes: Suggest ways to improve the stability of objects around them.

Introduction •

Through this activity, student build models by applying the concept of stability.

Materials and Apparatus • Carrot, wooden stick, potatoes (or any other fruit/ vegetables) What Do I Do? Step 1 1. Students are given a task to balance a carrot on their forefinger. (Student might find difficulty to balance the carrot. Discuss why it is difficult the carrot on their forefinger). Step 2 1. Using the materials provided, students are asked to improve the stability of the carrot on their forefinger. 2. They can stick the wooden sticks to any part of the carrot. What is Happening? The use of the wooden sticks is to widen the base area of the carrot. While, the potatoes are used to lower its centre of gravity. So the carrot will achieve stability and could stay upright on the forefinger.

Carrot

Potato Wooden stick

1.4.4

CLOWN BOB 15


Curriculum Specifications Link • • •

Theme : Technological and Industrial Development in Society Learning area : Stability Learning outcomes: Suggest ways to improve the stability of objects around them.

Introduction •

Through this activity, student build models by applying the concept of stability.

Materials and Apparatus • Ping pong ball, plasticine , manila card, coloured wool, scissor, glue and marker pen What Do I Do? 1. The idea of this activity is to make a clown that can bounce back to its upright position when it is pushes from any direction. 2. First, cut the ping pong ball into two halves. 3. Then filled one half of the ping pong ball with plasticine to make the base of the clown. 4. Decorate the body and head of the clown using a marker pen, wool and manila card . 5. Adjust the height of the clown if it cannot bounce back. What is Happening? The taller clown will bounce back slower than the shorter clown because of the position of the centre of gravity is higher. The centre of gravity affects the stability of an object.

16


1.4.5

A DOZEN NAILS

Curriculum Specifications Link • • •

Theme : Technological and Industrial Development in Society Learning area : Stability Learning outcomes:1) Relate the point of equilibrium as the centre of gravity of an object 2) Relate the centre of gravity to the stability of an object 3) Relate how the weight affect the stability of an object 4) Relate the size of base area to the stability of an object 5) Suggest ways to improve the stability of an object

Introduction This activity shows the relationship between centre of gravity and the stability of an object. This activity shows that you can balance 11 nails on a single nail as shown in the picture above. What Do I Need? • A dozen iron nail of the same size(4-5 inches) • A wooden board ( to stand the nail)/ plasticine • A hammer What Do I Do? 1. Hammer an iron nail into the wooden board /plasticine and ensure it stand still. 2. Arrange another 9 iron nails on one iron nail with all the heads of iron nails arranged next to each other on the table. (5 iron nails on one side and another 4 on the opposite side) 3. Place the last iron nail on the top of the iron nails that have been arranged. 4. Lift all the arranged nails and place them on top of the hammered nail. 5. Then, adjust the structure to stabalise on a single iron nail.

17


What is Happening? When the iron nails are arranged in a pattern of two sides comb on top of a single nail, the distribution of weight happened. The distribution of the weight throughout the structure is to make them stable.

18


2.0 MISCONCEPTIONS RATIONALE 1. Many misconception occur during the teaching and learning processes of certain topic in science 2. These misconceptions are transferred by the teachers to students which will eventually affect their perception towards the actual concept. 3. Teachers generally are unaware of these misconceptions and needs to be identified earlier. OBJECTIVES 1. To provide teachers with examples of misconceptions. 2. To help teachers to be more aware of the misconceptions which are frequently passed on to students without realising it. STRATEGIES 1. Before starting this topic, teachers are advised to go through the examples given to get a clear picture of some of the misconceptions. 2. Teachers are encouraged to identify other misconceptions that might occur in other topics. SUGGESTIONS Teachers are encourage to find other misconceptions that might occur during teaching and learning processes. Some examples are given below.

19


2.1 WATER AND SOLUTION 2.1.1 EVAPORATION OR BOILING?

Theme :

Issue:

Matter in Nature

Students are still not able to differentiate the differences between evaporation and boiling.

Learning Area:

Misconception:

Water and solution

The misconception here is that both processes refer to the same changes in the state of water from liquid to gas.

Learning Objectives:

Actual concept:

Analysing the process of evaporation of water

Teachers must stress on the different temperatures involve in both processes. Boiling only takes place at a constant / fixed temperature for a specific substance. i.e. Distilled water boils only at 100oC Evaporation of distilled water can occur at any temperature between 100oC (Boiling point) and 0oC (Freezing point)

Learning Outcomes: Suggestions: Compare and contrast between evaporation and boiling

1. The word “point” refers to a specific temperature. 2. Evaporation does not have a specific temperature or “point”. 3. Encourage students to use Graphic Organiser to identify the similarities and differences. Evaporation

Boiling Similarities

Differences

20


2.1.2

CONCENTRATED OR SATURATED?

Theme :

Issue:

Matter in Nature

When ask to explain the difference between concentrated and saturated solution, students often misunderstood that when a solute is added to a concentrated solution, a saturated solution is automatically formed even if the solute is still able to dissolve in it.

Learning Area: Misconception: Water and solution The misconception here is that a saturated solution is formed automatically after a concentrated solution is added with a solute. Learning Objectives:

Actual concept:

Analysing solution and solubility

A concentrated solution does not become saturated if the solute added can still dissolved. The solution becomes saturated when it contain the maximum amount of solute and is unable to dissolve anymore solute in a solvent.

Learning Outcomes: Contrast and compare between diluted solution, concentrated and saturated solution

Suggestions: 1. Students must carry out the activity suggested in the text book to show the ability of solutes to dissolve in a solvent. 2. Teacher must focus on the ability of the particles of a solute to dissolve in the solvent and not the ability of the solvent to absorb the particles of the solute. 3. Teachers must allow students to carry out the activity suggested in the text book first before the concept behind the different types of solution can be discussed and understood by the students i.e. Dilute, Concentrated and Saturated Solution. 4. Encourage students to use Graphic Organiser to show the similarities and differences.

21


2.1.3

SOLUBILITY

Theme :

Issue:

Matter in Nature

Students cannot distinguish between the factors affecting the solubility of a solute and the factors affecting the rate of dissolving.

Learning Area:

Misconception:

Water and solution

The misconception here is that students often make the mistake of assuming that the factor that affects the solubility of a solute is the same as the factors that affects the rate of dissolving. When asked about the factors that affects the solubility of a solute, students often answer stirring and the size of the solute as the factors.

Learning Objectives: Analysing solution and solubility

Actual concept: Teachers must stress that temperature affects both the: i. solubility of a solute and ii. rate of dissolving of a solute. however :

Learning Outcomes:

Solubility is influenced by: i. the nature of the solvent ii. the nature of the solute.

and

Explain the factors while: affecting the solubility of solutes in water The rate of dissolving is influenced by: i. stirring and ii. the size of the solute. Suggestions: 1. Teachers must first relate solubility with the activity carried out by students on dilute, concentrated and saturated solution. 2. Students must carry out the activity to observe how solubility is affected by the temperature, the nature of solvent and the nature of the solute. 3. Students must also carry out activity to show how the rate of dissolving is affected by temperature, stirring and the size of solute used. 4. Students should be able to see how temperature affects both the solubility and the rate of dissolving.

22


2.1.4

WHOSE COLOUR? Issue:

Theme : Matter in Nature

Teachers and students often explain the neutral point in neutralisation as the change in colour of the alkaline solution (from purple to green) instead of the change in colour of the Universal indicator.

Learning Area:

Misconception:

Water and solution

The misconception here is that students refer the change in colour of the alkaline solution but not the colour changes of the Universal indicator.

Learning Objectives:

Actual concept:

Analysing acids and alkali

Teachers must stress that the indicator is used to observe the colour changes to determine the neutral point in neutralisation. The Universal indicator itself is green and will change colour to red in an acidic medium or purple in an alkaline medium. Teacher should stress that the changes of colour is of the Universal indicator and not of the alkaline solution. Suggestions:

Learning Outcomes:

1. The word “changes colour� must refer to the Universal indicator and not to the medium (Acid or Alkali)

Explain the meaning of neutralisation

23


2.2 AIR PRESSURE 2.2.1

WHAT IS PRESSURE? Issue:

Theme : Matter in Nature

During this lesson, when students are asked to explain the application of air pressure in siphon and drinking straw, they often explain by relating air pressure to its volume in a closed container. Misconception:

Learning Area: Air Pressure

Learning Objectives: Applying the principle of air pressure in daily life

The misconception here is that the principle of air pressure in siphon and drinking straw is explained by relating the principle of air pressure in a closed container. Actual concept: Teachers must stress the concept of air exerts pressure and that air moves from a higher pressure to a lower pressure. In the case of siphon and drinking straw, when a higher atmospheric pressure moves to a lower pressure area, the liquid is pushed through the straw/siphon. Suggestions:

Learning Outcomes: Explain with examples things that use the principle of air pressure

1. Teachers must first help students recall that air exerts pressure. 2. Teachers must inform students that the relationship of volume and air pressure only applies to closed container but not to siphon and drinking straw. 3. Teachers must show a diagram on the movement of air pressure from a higher pressure area to a lower pressure area. Higher atmospheric pressure presses onto the water

Higher pressure Air pressure in the tube decreases as air is suck out

Water flows through Water flows out of the tank due to the difference in air pressure above and below the water tank.

24


2.3 DYNAMIC 2.3.1 What is Work done? Issue: Theme : Force and Motion

Students cannot understand why a girl standing while holding a book is not considered as work done. Misconception:

Learning Area: Dynamics

The misconception here is that students do not relate distance as an important factor in work done. . Actual concept:

Learning Objectives: Application of work

Teachers must stress that work is the product of the force acting on an object and the distance moved by the object in the direction of the force. Work done = Force(N) X Distance(m)

Suggestions: Learning Outcomes: Explain with examples how work is done

1. Teacher must stress on the concept that work is only considered done when a force is applied to move an object in a specific distance, in the same direction of the movement. 2. Teacher must give examples to compare the differences between the situation when work is done and when work is not done. 3. Teacher must help students recall and understand the unit of force (N) when using the formula : Work = Force(N) X Distance(m)

Distance moved (m)

25


2.3.2

WHICH DISTANCE? Issue:

Theme : Force and Motion

Students do not know the correct distance to use when calculating work done [ Work = Force(N) X Distance(m)]. Misconception:

Learning Area: Dynamics

The misconception here is that students assume that the distance of stair case as the distance to be used in calculating work done.

Actual concept: Learning Objectives: Application of work

The vertical distance (height) is the actual distance used in calculating work done. Distance of Stair case Vertical distance

Suggestions: Learning Outcomes: Explain with examples how work is done

1. Teachers should use diagrams to show the vertical distance of stair case. 2. Teachers should inform students that the vertical distance (height) of the stair case is the sum of the height of each stairs. 3. Teachers must emphasised the distance moved is in the same direction with the force 4. Teachers should carry out this activity on a real stair case in schools.

26


2.4 SUPPORT SYSTEM 2.4.1 PROP ROOTS OR STILT ROOTS. Theme : Force and Motion

Issue: Students are not able to differentiate between prop roots and stilt roots. Misconception: The misconception here is that both types of roots grow out from the stem for additional support.

Learning Area:

Actual concept:

Support System

Prop roots and stilt roots do grow out from the stem of plants. But prop roots of Maize plant grows from the nodes on the main stem while the prop roots of Banyan tree grows from the branches. Nodes

Learning Objectives: Understanding the support systems in plants Maize Plant

Banyan Tree

Whereby, stilt roots of Mangrove Plants develop from the main stem.

Learning Outcomes: Classify plants based on their support systems

Mangrove Plant Suggestions: 1. Teachers must stress that stilt roots develop from the main stem near the surface of the soil whereas prop roots develop from the nodes of the stem or branches. 2. The use of diagram/pictures of plants as examples is recommended. 3. Teachers are encouraged to take students for fieldwork.

27


2.5 OTHER EXAMPLES OF MISCONCEPTIONS 1 2 3

Mass and weight Excretion and defecation (digestion) Buoyancy with density

4

Why object float or sink with density Unit of volume Solid – cm3

5 6

Liquid - ml Terms of chloroplast and chlorophyll Unicellular and multicellular organism

7 8 9

-give specific example Mixture and compound Tropism (thigmotropism) and nastic movement Long-sightedness and short-sightedness

10 11 12 13 14 15

Different terms in English and Bahasa Melaysia Is fungi a plant? Plant carry out both respiration and photosynthesis What is the concept of moment of force? Difference between magnitude of force and force Difference between diffusion and absorption How to find out resistance in parallel circuit and serial circuit

3.0

GLOSSARY

The students can be motivated to learn up scientific terms and words in English.

A few examples are given that can help to enhance a student’s vocabulary.

It must be noted that the students are given a list of scientific terms to be learnt prior to a lesson.

In addition they should look up the meaning of these words prior to a lesson.

28


A few examples of activities in class are given as below.(for enhancement during or after related lesson.)

Activity 1 – Word Power for 1.1 Physical Characteristics of Water Activity 2 – Word Jumble for 1.2 Composition of Water Activity 3 – Crossword Puzzle for 1.3 Evaporation of Water

29


3.1

WATER AND SOLUTION Technique used

3.1.1

Word Power

PHYSICAL CHARACTERISTICS OF WATER

Theme Matter in nature

Aim To analyse the physical characteristics of water.

Learning Area Water and solution

Materials Word power handout, activity sheet for word power

Duration 15 minutes

Activities (10 minutes) 1.

Keywords 2. I melting point takat lebur

3.

ii freezing point takat beku iii boiling point takat didih iv impurities bendasing v colourless tiada warna

Before teaching this topic teacher provides students with the word power handout. Students read through the word power handout to understand the meaning of each term.( 5 minutes ) At the end of the lesson teacher distributes activity sheet for word power and asks the students to complete the table with correct terms. ( 5 minutes )

Evaluation ( 5 minutes ) 1 2 3 4

Students answer the activity sheet in the class. Teacher discusses the answers with the students. Students with wrong answers are required to do corrections. Students with good achievement are rewarded. (optional)

vi tasteless tiada rasa vii ordourless tiada bau viii steam stim ix

heat haba

30


a)

Word Power Physical Characteristics of Water

No

Term

Meaning

1

melting point takat lebur

The temperature at which a solid changes into a liquid.

2

freezing point takat beku

The temperature at which liquid turns into solid state.

3

boiling point takat didih

The temperature at which a substance changes from the liquid state to the gaseous state.

4

impurities bendasing

A substance that is present in small amounts in another substance that lowers the freezing point and increases the boiling point.

5

colourless tiada warna

No colour.

6

steam stim

Water in gaseous form.

7

heat haba

Warmth or how hot something is; a form of energy which may be transferred by conduction, convection or radiation.

31


Activity Sheet for Word Power Physical Characteristics of Water

Name:……………………………………………………………………Class:…………......

No

Term

Meaning

1

The temperature at which a solid changes into a liquid.

2

Water in gaseous form.

3

A substance that is present in small amounts in another substance that lowers the freezing point and increases the boiling point.

4

The temperature at which liquid turns into solid state.

5

No colour.

6

Warmth or how hot something is; a form of energy which may be transferred by conduction, convection or radiation.

7

The temperature at which a substance changes from the liquid state to the gaseous state.

32


Technique used

3.1.2

Word Jumble

Theme Matter in nature Learning Area Water and solution Duration 15 minutes Keywords i

anode anod

ii

cathode katod

iii compound sebatian

Aim To analyse composition of water. Materials Word power handout, activity sheet for word jumble. Activities(10 minutes) 1 Before teaching this topic teacher provides students with the word power handout. 2 Students read through the word power handout to understand the meaning of each term.( 5 minutes ) 3 At the end of the lesson teacher distributes activity sheet for the students to rerarrange the alphabets to form the correct spelling term .( 5 minutes ) Evaluation ( 5 minutes )

iv electrolysis elektrolisis

1 2 3

v

4

discharge nyahcas

COMPOSITION OF WATER a) WORD JUMBLE

Students answer the activity sheet in the class. Teacher discusses the answers with the students. Students with wrong answers are required to do corrections. Students with good achievement are rewarded. (optional)

vi electrode elektrod

33


Word Power Composition of water No

Term

Meaning

1

anode anod

The electrode that is connected to the positive terminal of a battery.

2

cathode katod

The electrode that is connected to the negative terminal of a battery.

3

compound sebatian

A substance made up of two or more elements which are chemically combined.

4

electrolysis elektrolisis

The process of separating a compound into simpler substances by passing an electric current through it.

5

discharge nyahcas

Change of an ion to its element on an electrode during the electrolysis process.

6

electrode elektrod

A solid conductor, usually a metal or carbon, placed in an electrolyte to allow an electric current to enter or leave during electrolysis.

34


Activity Sheet for Word Jumble Composition of Water

Name:……………………………………………………………………Class:…………...... Rearrange the alphabets to form the correct terms. No

Term

1

ondae

2

…………… oedchta ……………….

3

mundcoop ……………….

4

cylreselosit

Meaning The electrode that is connected to the positive terminal of a battery. The electrode that is connected to the negative terminal of a battery. A substance made up of two or more elements which are chemically combined.

The process of separating a compound into substances by passing an electric current through it.

simpler

………………. . 5

ciadgrshe ………………..

6

doetcrele ……………….

Change of an ion to its element on an electrode during the electrolysis process. A solid conductor, usually a metal or carbon, placed in an electrolyte to allow an electric current to enter or leave during electrolysis.

35


Technique used

3.1.3

Crossword Puzzle

EVAPORATION OF WATER a) CROSSWORD PUZZLE

Theme Matter in nature

Aim To analyse the process of evaporation of water.

Learning Area Water and solution

Materials Word power handout, crossword puzzle.

Duration 15 minutes

Activities( 10 minutes) 1.

Keywords 2. preservation pengawetan

3.

evaporation penyejatan

Before teaching this topic teacher provides students with the word power handout. Students read through the word power handout and to relate the terms with the correct meanings.(5 minutes) At the end of the lesson teacher distributes the crossword puzzle and asks students to solve the crossword puzzle using the correct terms for every clues given.( 5 minutes)

humidity kelembapan Evaluation( 5 minutes) surface area luas permukaan boiling pendidihan

1 2 3 4

water vapour wap air

Students answer the crossword puzzle in the class. Teacher discusses the answers with the students. Students with wrong answers are required to do corrections. Students with good achievement are rewarded. (optional)

36


WORD POWER Evaporation of Water No

Term

Meaning

1

preservation pengawetan

A process to protect substance from damage or decay.

2

evaporation penyejatan

Process of changing a liquid to a gas at any temperature below the liquid’s boiling point.

3

humidity kelembapan

The amount of water vapour in the air.

4

surface area luas permukaan

The measure of how much exposed area an object has.

5

boiling pendidihan

The change from a liquid to a gas at its boiling point.

6

water vapour wap air

Water in the gaseous state.

37


1

Go to this web sites http://www.puzzle-maker.com/CW/

2

Follow the instruction given by the web sites to create the puzzle. Example of words and clues for puzzle: Preservation / A process to protect substance from damage or decay. Evaporation / Process of changing a liquid to a gas at any temperature below the liquid’s boiling point. Humidity / The amount of water vapour in the air. Surface area / The measure of how much exposed area an object has. Boiling / The change from a liquid to a gas at its boiling point. Water vapour / Water in the gaseous state.

3

Print screen the web page and then paste it in PAINT software.

4

Cut out what is required and paste it in MICROSOFT WORDS.

38


Crossword puzzle in class Name:……………………………………………………………………Class:…………......

ACROSS 5 Process of changing a liquid to a gas at any temperature below the liquid’s boiling point. 6 The change from a liquid to a gas at its boiling point. DOWN 1 The measure of how much exposed area an object has. 2 A process to protect substance from damage or decay. 3 Water in the gaseous state. 4 The amount of water vapour in the air.

39


Solution to crossword puzzle in class

40


3.2 PHYSICAL CHARACTERISTICS OF WATER a) CROSSWORD PUZZLE

…. ..

41


42


4.0 EXPERIMENTING 4.1 IDENTIFYING VARIABLES Activity 1.1: ANALYSING THE PROCESS OF EVAPORATION OF WATER

Diagram 1.1 Constant variables: movement of air, surface area, temperature. 1. Teacher asks the students to list out all the factors that affect the rate of evaporation of water i.e. movement of air, surface area, temperature and humidity. Diagram 1.2 2. Teacher stresses that Activity 1.1 is to show that humidity affects the rate of evaporation of water. 3. Since we want to study the effect of humidity on the rate of evaporation of water, other factors such as movement of air, surface area and temperature should be kept the same and they are called constant variable. Manipulated variables: humidity 1. Teacher asks the students to observe and compare Diagram 1.1 and Diagram 1.2 for any differences. [Is there any difference between bell jar A and bell jar B?] [What is the difference between bell jar A and bell jar B?] 2. Students should be able to mention that bell jar B has anhydrous calcium chloride. 3. Teacher asks the students the function of the anhydrous calcium chloride. 4. The teacher tells the students the correct answer (anhydrous calcium chloride absorbs water vapour / moisture from the air). 5. Teacher asks the students to compare the condition of the air in both bell jars. The air in bell jar B is drier than the air in bell jar A. [Air in bell jar A contains more water vapour than the air in bell jar B. Humidity depends on the amount of water vapour in the air. The more water vapour in the air the higher the humidity]

43


6. Teacher stresses on the terms of “humidity � (amount/quantity of water vapour/moisture in the air). 7. The factor that is not the same in both situations is the humidity. This factor is called manipulated variable. Responding variables: rate of evaporation 1. Teacher asks the students to observe the volume of water in the watch glass in both bell jars before the experiment. 2. After 10 minutes, more water had evaporated from the watch glass in the bell jar B compared to bell jar A. 3. Teacher asks the students to observe the difference of volume of the water left in the watch glass in both bell jars. 4. The difference of volume of water in the watch glass in both bell jars is the responding variable.

Activity 1.2 To show that movement of air affects the rate of evaporation of water. Manipulated variables: movement of air 1. Activity 1.2 is carried out to show that movement of air affects the rate of evaporation of water. 2. Teacher asks the student to fill two watch glasses with 0.5 cm 3 of water.

44


3. Teacher asks the students to use the syringe to blow the air on one of the watch glasses. 4. Teacher asks the students which watch glass gets drier faster. (Watch glass that being blown). 5. Teacher asks the students to state the factor that affects the evaporation of the water in the watch glass that gets drier faster (movement of air/wind). 6. Factor that affects the evaporation of water is the variable that is manipulated. 7. Teacher asks the students to identify the manipulated variable. Constant variables: temperature, humidity, surface area of water. 1. Teacher asks the students to list out all the factors that affect the rate of evaporation of water. i.e. temperature, humidity, surface area of water and movement of air. 2. Teacher stresses that Activity 2 is to show that movement of air affects the rate of evaporation of water. 3. Other factors such as humidity, surface area and temperature are kept the same and they are called constant variables. Responding variables: rate of evaporation 1. Teacher asks the students to observe the amount of water in both watch glasses. 2. Teacher tells the students the differences of the volume of water left refers to the responding variable. The rate of evaporation is faster in one of the watch glass. The teacher stress out the terms rate of evaporation to the students.

Activity 1.3: Analysing solution and solubility

Beaker A

Beaker B

45


Diagram 1.3

Manipulated variables: types of solute 1 . Teacher asks the students to observe and compare the two beakers in Diagram 1.3 for any differences. 2. Students should be able to mention that the solute in Beaker B is different from solute in Beaker A. 3. Students should be able to mention that the type of solute is manipulated variable.

Responding variables: The solubility of solute 1. Teacher asks the students to observe both beakers in Diagram 1.3. 2. Teacher asks the students to observe the maximum mass of solute (sodium chloride or sugar) that can dissolve in the certain amount of water at a specific temperature. More amount of sodium chloride dissolves in water than sugar. 3. The teacher stress out to students that different solute has different solubility in water. Student should be able to give the correct responding variable.

Constant variables: amount of distilled water , nature of solvent and temperature . 1. Teacher asks the students to list out all the factors that affect the solubility of a solute. Students will list out as many variables as they can but the teacher must make sure that these variables are included : amount of distilled water ,nature of solvent and temperature.

46


2. In Diagram 1.3, what are the things that are the same in both beakers ( volume of distilled water , nature of solvent and temperature). 3. The constant variables are the things that are kept the same through out the activity.

Activity 1.4: Analysing solution and rate of dissolving

47


Diagram 1.4 Manipulated variables: rate of stirring 1 . Teacher asks the students to observe and compare for any differences between Beaker A and Beaker B. 2. The students should be able to mention that the stirring in the Beaker B is faster than in Beaker A. 3. The students should be able to state the manipulated variable (rate of stirring). , Constant variables: temperature, amount of water, amount of salt, type of salt 1. Teacher asks the students to list out all the factors that affect the rate of dissolving. Students will list out as many variables as they can but the teacher must make sure that these variables are included : temperature, amount of water, amount of salt, type of salt. 2. In Diagram 1.4, what are the things that are the same in both beakers (volume of distilled water, amount/quantity of solute, type of solute). 3. The constant variables are the things that are kept the same through out the activity. Responding variables: rate of dissolving 1. Teacher asks the students to observe the fine salt in both beakers. 2. Teacher tells the students that the faster they stir the solution the faster the salt dissolves. 3. Teacher explains to the students that the rate of dissolving of salt is the responding variable. Student should be able to give the responding variable. Activity 1.5 : To show that the size of solute particles affect the rate of dissolving

48


Beaker A

Beaker B 1 g of coarse salt

1 g of fine salt

Diagram 1.5 Manipulated variables: size of solute 1 . Teacher asks the students to observe and compare the materials given. [What is the difference between the salt in Beaker A and the salt in beaker B? (course salt and fine salt). 2. Students should be able to mention that the difference is the size of the solute. 3. The size of the solute is the manipulated variable.

Constant variables: temperature , mass of solute , volume of solvent and the rate of stirring 1. Teacher asks the students to list out all the factors that affect the rate of dissolving. Students will list out as many variables as they could but the teacher must make sure that these variables are included : temperature, mass of solute , volume of solvent and the rate of stirring. 2. In Diagram 1.5, what are the things that are the same in both beakers (rate of stirring and temperature) 3. The constant variables are the things that are kept the same through out the activity.

Responding variables: rate of dissolving 1. Teacher asks the students to observe the solute in both beakers in Diagram 1.5.

49


2. Teacher asks the students which solute/type of salt dissolve faster (the fine salt). 3. Teacher explains to students that the rate of dissolving the solute is the responding variable.

4.2 DEFINING OPERATIONALLY Activity 1: Analysing acid . 50


Things that should be done: 1. Teacher dips the blue litmus paper into lemon juice. 2. Teacher tells the students to observe the colour changes of the litmus paper ( blue to red.) 3. Teacher ask the students what she did and what they observed. Teacher explains that defining operationally refers to what has been done and what was observed. 4. Therefore acid is defined operationally as : Acid is a substance that turns blue litmus paper to red when the blue litmus paper was dipped into the lemon juice.

51


Activity 2: Analysing alkali. Things that should be done: 1. Teacher dips the red litmus paper into lime water . 2. Teacher tells the students to observed the colour changes of the red litmus paper (red to blue.) 3. Teacher ask the students what she did and what they observed. Teacher explains that defining operationally refers to what has been done and what was observed. Based on your findings, define operationally what is alkali. Alkali is a substance that turns red litmus paper to blue when it is dipped into the lime water.

52


Activity 3: Analysing rate of dissolving A pupil carries out an experiment to study the effect of temperature of solvent on the rate of dissolving of sugar. The time taken for sugar to dissolve completely in water is shown by stopwatch in Diagram 1.1

50 cm3 water 20 0C

100 g fine sugar

Beaker A

50 cm3 water 40 0C

100 g fine sugar

Beaker B

50 cm3 water 60 0C

100 g fine sugar

Beaker C

100 g fine sugar

50 cm3 water 80 0C

Beaker D

53


50 cm3 water 90 0C

100 g fine sugar

Beaker E

DIAGRAM 3.1

( a ) Based on Diagram 3.1, complete Table 3.2 by recording the time taken on the respective temperature of water. Temperature of water / 0 C

20

40

60

80

Time taken for sugar to dissolve completely / s

55

44

37

20

90

11

Table 3.2 (b) State the variables involved in this experiment. Manipulated variable

Temperature of water

Responding variable

Time taken completely

Controlled/constant variable

Volume of water // quantity of sugar

(c)

for

sugar

to

dissolve

Based on Table 3.2, define operationally “rate of dissolving�. Rate of dissolving is the time taken for 100 g of sugar to dissolve completely in different temperature of water,

(d) Based on the results, what will happen to the time taken to dissolve sugar in water completely if the temperature of water is more than 100 0C? The time taken will decrease // Time taken for dissolving sugar will become shorter.

54


Activity 4 :Analysing the effect of temperature on air pressure A student carries out an experiment to study the effect of temperature on air pressure. Diagram 4.1 shows the arrangement of apparatus for the experiment.

DIAGRAM 4.1 The student takes the following steps: 1. The apparatus is set up as shown in Diagram 4.1. 2. The water bath is heated until the temperature of water reaches 30 0C and record the Bourdon gauge reading. 3. Repeat step 2 with temperatures of 400C, 500C, 600C and 700 C. (a) (i ) Record the Bourdon gauge reading in the space provided. .

The temperature of water = 300 C Bourdon gauge reading = 105 kPa

55


The temperature of water = 400 C Bourdon gauge reading = …109. kPa

The temperature of water = 500 C Bourdon gauge reading = …112.. kPa

The temperature of water = 600 C Bourdon gauge reading = …115.. kPa

The temperature of water = 70OC Bourdon gauge reading = ..119..kPa

DIAGRAM 4.2

56


DIAGRAM 2.2

(a) (ii)

DIAGRAM 2.2

Based on Diagram 4.2, complete Table 4.1 by recording the Bourdon gauge reading on the respective temperature of air.

Temperature ( 0 C) Bourdon gauge reading ( kPa)

30

40

50

60

70

105.0

109.0 …….

112.0 …….

115.0 …….

119.0 …….

TABLE 4.1 (b)

State the variables involved in this experiment.

. Manipulated variable

Temperature of water

Responding variable

Bourdon gauge reading

Controlled variable

Size of round bottom flask

(c)

Based on the activity, define operationally “air pressure”? Air pressure is the reading of Bourdon gouge when the water is heated.

57


Activity 5 : Analysing the extension of spring A group of students sets up an apparatus as shown in Diagram 5.1. The pendulum bobs of different weights are used. The extension of the spring is recorded for each pendulum bob.

Metre rule

Spring

Pointer

Pendulum bob

DIAGRAM 5.1 The pupil takes the following steps :Step 1 : Hang a 20 N pendulum bob to a spring. Step 2 : Take the reading of metre rule Step 3 : Repeat step 1 and step 2 by using pendulum bob with the weights of 40 N, 60 N, 80 N and 100 N respectively. (a)

Record the pointer reading in the space provided

20 The weight of pendulum bob = 20N Pointer reading = 20.5 cm 21

58


20

The weight of pendulum bob = 40N Pointer reading = …20.9. cm

21

21

The weight of pendulum bob = 60N Pointer reading = …21.3. cm

22

21

The weight of pendulum bob = 80N Pointer reading = …21.7. cm 22

21

The weight of pendulum bob = 100N Pointer reading = …22.1 cm

22

59


(b) State the variable in the experiment. Manipulated variable

Weight of pendulum bob

Responding variable

The extension of spring

Controlled variable

Type of spring

(c) Define operationally “extension of the spring�. Extension of the spring is the reading of metre rule when different mass of pendulum bob is used.

60


Activity 6 : Analysing frictional force A student carried out an experiment to study the effect of different types of surfaces on frictional force. The readings of the spring balance when the wooden block is pulled along different surfaces are shown in Diagram 4.1.

5

4

4

3

Wooden block

block

Glass surface

Wooden block

Marble top

Cement floor DIAGRAM 4.1

61

5

6

Wooden block block


(a) State the variables involved in the experiment. Manipulated variable:

Types of surface

Responding variable:

Extention of spring // Reading of spring balance

Controlled variable:

Weight of wooden block // type of spring

(b) Based on Diagram 4.1, record the readings of the spring balance in Table 4.2. Type of surface

Reading of spring balance (N)

Glass surface

4.5

Marble top

3.8

Cement floor

5.2 TABLE 4.2

(c) Define operationally “frictional force�. Frictional force is the reading of spring balance when the wooden block is pulled along different types of surfaces.

62


pmr