CP Chemistry
Chapter 3 – Study Guide
Test Date: Thursday, October 16, 2014
Use the following to study:
Textbook – Chapter 3
Ch. 3 PPT notes
Ch. 3 packet
Chapter Three

History of Atomic Theory
o Democritus
o Dalton
 Dalton’s Atomic Theory
 What was incorrect about Dalton’s theory?
o JJ Thompson
 Cathode Ray Tube Experiment and results (what is he credited with
discovering?)
 Plum Pudding Model of the atom (be able to describe)
o Robert Millikan
 Oil Drop Experiment and results
o Earnest Rutherford
 Gold Foil Experiment
 What did Rutherford expect to see in his experiment based on the Plum
Pudding Model? What did he actually see? What conclusion did he
come to as a result of this?
 Nuclear Model of the atom
o James Chadwick
 Discovered the neutron in 1932

Three Basic Laws
o Law of Conservation of Mass
o Law of Definite Proportions
o Law of Multiple Proportions

Structure of the Atom
o Nucleus – what is inside of it? What is its mass compared to the whole atom?
o Subatomic particles – protons, electrons, neutrons
 What are their charges? Where are they found inside the atom? Which two
have essentially the same mass? Which one is so small its mass is ignored?
o The majority of the atom is_______________________________________.
o Nuclear forces – what are they? What are the responsible for?
o Atomic Radius – what does it measure? What units is it measured in?

Determining Subatomic Particles in an Atom
o Atomic Number = # of protons (and # of electrons in a neutral atom)
o Mass Number = # protons + # neutrons

Isotopes
o Definition
o What is different among isotopes (2 things)? What must always be the same?
o know the difference between percent abundance & relative abundance
o calculations of average atomic mass and its units!

Isotope Notation
o Nuclear Notation (example below)
o


(know what the 8 & 16 represent)
Hyphenated Notation
 Oxygen-16 (know what the 16 represents)
The Mole & Molar Conversions
o What does the mole represent?
o Avogadro’s # will be given to you on the day of the test (6.022 x 1023 atoms/mol)
o Molar Mass – definition, units, determining molar mass of elements
o Molar Conversions (must use dimensional analysis!!!)
 Grams  Moles (and reverse)
 Atoms  Moles (and reverse)
 Grams  Atoms (and reverse)… these ones are the two step problems
o On the test you will only be given the following:
 You MUST use DIMENSIONAL ANALYSIS to solve these problems… the map
below is only a guide to help you think through the problem
The Mole Map:
Grams  Moles  Atoms