1. Ch. 13 Models of Atoms

2. “Plum pudding” atom negatively charged e - stuck into a lump of positively charged material – similar to chocolate chip cookies J.J. Thomson

3. “The Blow Pop” Ernest Rutherford In Rutherford’s gold foil experiment he discovered electrons surround a dense positive nucleus.

4. Bohr Model electrons are arranged in fixed orbits around the nucleus, called electron shells. Like planets revolving around the sun. ex. Orbits gum

5. Bohr Model cont. Electrons found in the shells: 1 st shell can have up to 2e- 2 nd shell can have up to 8e- 3 rd shell can have up to 18e- 4 th shell can have up to 32e- The outermost shell cannot have more than 8e- (atoms bond with other atoms to try to get 8e- in their outermost shell).

6. Quantum Mechanical Model Quantum mechanics was developed by Erwin Schrodinger Estimates the probability of finding an e - in a certain position Electrons are found in an “electron cloud”