1. History of Atom Flip Book
The atom
Picture, parts including charge and location
Chadwick
Discovered the…
Rutherford
Gold Foil Experiment
JJ Thomson
Cathode Ray Tube
Millikan
Oil Drop experiment
Dalton
Dalton’s Atomic Theory
Democritus
His 5 ideas
Aristotle
Link with nature (Figure 4-1)
History of Atom Flip Book

2. History of the atoms
Matter is composed of empty space through which atoms move
Atoms are solid, homogeneous, indestructible, and indivisible
Different kinds of atoms have different sizes and shapes
Differing properties are due to the size, shape and movement of atoms
Changes in matter result from the changes in groupings of atoms
Matter is composed of air, fire, water, and Earth
His popularity allowed his ideas to persist into the 1800’s.

3. Dalton’s Atomic theory
All matter is composed of extremely small particles called atoms
All atoms of a given element are identical
Atoms can not be created, divided, or destroyed (Law of Conservation of Mass)
Different atoms combine in simple whole number ratios to form compounds (Law of Definite Proportions)
In a chemical reaction, atoms are separated, combined, or rearranged
Unlike Democritus, Dalton proved his ideas with science experiments.

4. Subatomic Particles JJ Thomson Found charge to mass ratio of electron
Proved atoms were divisible into smaller subatomic particles—Big Shock to Science Community
Cathode Ray Tube
Would later create the Plum Pudding Model

5. Subatomic Particles Millikan Oil drop experiment
Found the charge of one electron
Electron charge = 1.602x10-19 coulombs
Accepted as -1 charge

6. Subatomic Particles Ernest Rutherford Gold Foil Experiment
Shoot positive particles at gold foil

7. Subatomic Particles Ernest Rutherford Gold Foil Experiment
Found that most positive shots went straight through but some bounced back
Atom was largely empty space through which electrons moved
Atoms contained tiny dense region called a nucleus that contained most of the mass
An atom the size of two football fields would have a nucleus the size of a nickel

8. Subatomic Particles Chadwick Discovered the neutrons
Neutrons act to separate the + protons so that they don’t repel each other

9. Atom
Smallest particle of an element that retains the properties of the element