1. Multi-electron atoms and the Periodic Table We cannot solve Schrödinger’s equation for multielectron atoms. Bummer. Nevertheless, we extend our understanding of the H atom wavefunctions to multielectron atoms in an approximate fashion.

2. What’s the same? Same quantum numbers apply and have the same meaning. Same rules apply to the possible values of quantum numbers. Same orbital types and nodal properties. What’s different? Atomic number impacts on orbital energies. Electron-electron interactions are present: electron shielding. Orbital energy degeneracies for given n are lost (energy depends on both n and l but not m l ).

3. E 1s 2s 2p 3s 3p 3d 4s 4p 4d 6s 5p 5d 4f 5f Multi-electron atoms 5s 6p 7s 6d 7p Order: 1s2s2p3s3p4s3d4p5s4d5p6s4f5d6p7s5f6d7p

4. 8s 7s 6s 5s 4s 3s 2s 1s 7p 6p 5p 4p 3p 2p 6d 5d 4d 3d 5f 4f

5. For atoms in the ground state, electrons will occupy the lowest energy orbital possible. For the H atom, this is the 1s orbital. We describe the manner in which the electrons are organized around a nucleus as its electron configuration. There are several ways of expressing electron configurations: Spectral notation: Box diagrams:

6. On to He. The Pauli Exclusion Principle: no two electrons can have the same set of four quantum numbers. No orbital can house more than two electrons. He Li Be B 1s 2s 2p1s2s 2p1s2s

7. C 2p1s2s2p1s2sor Hund’s rule: when electrons occupy orbitals of the same energy, the most stable arrangement is that with the maximun number of parallel spins. Paramagnetic: Diamagnetic:

9. Na-Ar K, Ca, Sc, Cr, Mn, Cu, Zn-Kr Cs, Ba, La, Ce-Lu, Hf

14. Atomic radii, Å