1. Page 11-14 Review questions: Page 16, #1,2,3,4,7
Atomic Theory
Page 11-14
Review questions: Page 16, #1,2,3,4,7

2. History of the atom What is an atom? What is it made up of?
What does it look like?
What properties does it have?

3. John Dalton (1809)
He thought atoms were solid spheres, like billiard balls
Proposed theory:

4. J.J. Thomson (1897) Discovered particles smaller than
atoms that were ___________ charged
Called it the ____________
Thought they were spaced evenly
throughout Dalton’s “spheres”, like
blueberries in a muffin
Electrons in a cathode ray tube

5. Ernest Rutherford (1909) Gold foil experiment
Shot high energy alpha particles (a helium
nucleus) at very thin foils of gold
Observed:

6. Ernest Rutherford (1909) Gold foil experiment
Shot high energy alpha particles (a helium
nucleus) at very thin foils of gold
Concluded:

7. James Chadwick (1932) Discovered the __________, a
____________ charged particle
also found in the nucleus

8. Niels Bohr (1920)

9. Niels Bohr (1920)

10. Niels Bohr (1920) Electrons are not randomly scattered around an atom
Instead, found:
Like _______________
First orbital holds __ electrons
Second holds __ electrons
Third orbital holds __ (up to __) electrons
Gets more complicated with more than 20 electrons

11. Bohr-Rutherford Diagrams Know how to draw!