1. Atomic Physics Physics 100 Chapt 24 Dimitri Mendeleev

2. Periodic table of elements Elements in vertical rows have similar chemical properties Inert gasses

3. Schroedinger’s Equation for multi- electron Atoms - - - - - +

4. Allowed energy levels are clustered in “shells” + - -- - - - - - - - - - - - - - - - n # of states 1 2 2 8 3a 8 3b 10 4a 8 4b 10 4c 14

5. Pauli exclusion principle Only one electron per quantum state Once a quantum state is occupied additional electrons are excluded Wolfgang Pauli

6. Light elements +1 - +2 - - Hydrogen Helium +3 - - Lithium - +10 - -- - - - - - - - Neon 1 electron in outermost shell outermost shell is full

7. Periodic table of elements Elements in vertical rows have similar chemical properties 1 e - in outer shell Filled outer shell

8. Chemical properties depend upon the outermost shell configuration +8 - -- - - - - - Oxygen +16 - - - - - - - - - - - - - - - - Sulfur Outermost shells Have 2 vacancies

9. Periodic table of elements 2 vacancies in outer shell

10. Atoms combine to form molecules by filling outer shells +8 - -- - - - - - Oxygen +1 - Hydrogen +1 - Hydrogen Water=H 2 O

11. Atoms combine to form molecules by filling outer shells +6 - -- - - - Carbon +1 - Hydrogen +1 - Hydrogen Methane=CH 4 +1 - Hydrogen +1 - Hydrogen

12. Elements with full outer shells don’t form molecules +2 - - Helium +10 - - - - - - - - - - Neon +18 - - - - - - - - - - - - - - - - - - Argon Noble gasses

13. Periodic table revisited Elements in vertical rows have same outer shell configurations Outer shell is full 1 elec in outer shell 2 vacancies in outer shell 4 e - in outer shell