Chemistry Chapter 2

Front 1

Neutron

Back 1

• similar mass of protons
  
• isotopes exist because neutrons have different number of neutrons but same # of protons they still are identified as the same element
  

Front 2

Isotopes

Back 2

• An element can have types of atoms with different masses and be chemically indistinguishable
  
• this disproved Dalton's Atomic Theory
  
• isotopes have: same atomic #, diff mass #
  

Front 3

Atomic Theory

Back 3

1. Matter is composed of atoms
   

i. atom is the smallest unit that can participate in a chemical change

2. Elements are composed of atoms

i. all atoms of the same element are alike

ii. all atoms of other elements are different

3. Compound is composed of 2+ elements combined in small whole # ratio's

Atoms can not be created or destroyed in a chemical change-- the atoms are just rearranged

Front 4

Law of Multiple Proportions

Back 4

When 2+ elements react to form more than 1 compound- a fixed mass of one element will react with masses of the other element in small whole # ratio's

Front 5

Cathode Ray Tube

Back 5

• particles are attracted by (+) q and repelled by (-) q-- so must be (-) charged
  
• less massive than atoms
  
• must be fundamental subatomic constituents of all atoms
  
• called the particle an electron
  

Front 6

Oil Drop Experiment

Back 6

• measured charge of single electron= 1.6e-19
  
• charge to mass ratio: 1.759e11C/kg
  
• mass: 9.107e-31
• disproved Dalton: atoms was no longer indivisible!!!!

Front 7

Gold Foil Experiment

Back 7

• volume occupied by an atom = a lot of empty space
• nucleus is at the center of each atom
• proton