St. George's College
8th CHEMISTRY Class:
Link and Learn
8th Milton A ‐ Atomic Calculations Name
Sergio María Fernanda Alejandra Almendra Anna Paula Sandra E‐C Maia María Belén Alfredo Kinley Arianne Sandra M. Fiorella Rodrigo Giulia Jaime Stefano Bruno
8th Milton Alpha ‐ Atomic Calculations Name
Marcelo Antonella Paulo Alejandro Brenda Diego Gabriel Valeria Cristina Giuliana Joshua María Gracia Gonzalo N. Paolo Gonzalo R. Giorgio Nicolás María Claudia
ATOMIC CALCULATIONS 4
Problem 1 Chromium exists in four isotopic forms. The atomic masses and percent occurrences of these isotopes are listed in the following table: Isotopic Mass (amu)
Isotopic Mass (amu)
Calculate the average atomic mass of chromium.
More Problems Calculate the atomic mass of the following elements according to the occurrence of their isotopes: 1. 1H (99.985%) ‐ 2H (0.015%) 2. 6Li (7.42%) ‐ 7Li (92.58%) 3. 10B (19.78%) ‐ 11B (80.22%) 4. 35Cl (75.53%) ‐ 37Cl (24.47%) 5. 35Ar (0.337%) ‐ 38Ar (0.063%) ‐ 40Ar (99.6%)
Teacher's Notes This class has been designed to cover the topics of Atomic Calculations for the week of Monday April 13th till Wednesday April 17th. For further knowledge about this topic: 1. Conduct a thorough search under the topic: Atomic Calculations on the Web, books and magazines. 2. If findings are not specific, ask your teacher for suggestions.
Objectives • Carry out mathematical calculations in chemistry, with emphasis in atomic masses.
Note: All, or most, of the objectives will be covered during class time, however the student must be responsible for those objectives not covered or concluded.
Vocabulary • Atom: the smallest unit of an element that still has the properties of that element. • Proton: a subatomic particle that has positive electric charge. • Nucleus: the control center of a cell that directs the cell's activities. The center of an atom, usually made of protons and neutrons. • Neutron: a subatomic particle that has the same mass as a proton but no electric charge. • Electron: a subatomic particle that orbits an atom's nucleus, has a negative electric charge, and has very little mass. • Atomic Number: the number of protons in an atom. • Element: a substance made up of only one kind of element. • Metal: a substance that conducts heat and electricity well and is malleable. • Nonmetal: a substance that does not conduct electricity and is not malleable. • Proton: a subatomic particle that has a positive electric charge. • Periodic Table: a table that shows the elements arranged by their atomic numbers. • Compound: a substance made up of atoms of two or more elements that are chemically combined. • Melting Point: the temperature at which a substance changes from a solid to a liquid. • Boiling Point: the temperature at which a substance changes from a liquid to a gas. • Plasma: a state of matter made up of charged atoms, uncharged atoms, and free electrons.
Note: Most of the vocabulary words will be covered during class time, however the student must be responsible for those words not covered or concluded.
Link and Learn You can visit the following websites to improve your understanding on the present topic: • • • • •
http://www.creation‐science‐prophecy.com/C14a.htm http://science‐learning2009.wikispaces.com http://learningandscience.blogspot.com www.sanjorge.edu.pe http://libraryatstgeorges.blogspot.com
Resources Used Slide
G1 ‐ 2 Image
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Helium Isotopes Carbon 14 Isotopes
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Carbon 14 formation
G1 ‐ 9 Animation Periodic Table
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Carbon ‐ Nitrogen reaction http://bit.ly/MSA0V http://bit.ly/2pNa39 Beta decay 1 http://bit.ly/13Rciv Beta decay 2
G1 ‐ 11 Images
Carbon 14 to Nitrogen 14‐1 http://bit.ly/h7Cxr Carbon 14 to Nitrogen 14‐2
E‐Portfolio G1 ‐ 12 Images Animation Puzzle pieces Copy and Paste Idea
http://bit.ly/W7ccA http://bit.ly/Dbbtf http://bit.ly/2ZxTj Notebook Gallery
G1 ‐ 14 Image
Gerardo LAZARO Science Lead Teacher Email: firstname.lastname@example.org Wiki: http://science‐learning2009.wikispaces.com Blog: http://learningandscience.blogspot.com Twitter: http://twitter.com/glazaro
Elemental Jeopardy 3 people.ppt