1. Why is the periodic table shaped like it is and how are the elements arranged?

3. Elements are arranged according to atomic #
and e- configuration.
Li: 3 e-’s 1s2 2s1
Na: 11 e-’s 1s2 2s2 2p6 3s1
K: 19 e-’s 1s2 2s2 2p6 3s2 3p6 4s1
Paramagnetic or diamagnetic?

4. Valence orbitals: outer shell orbitals
beyond the closest noble-gas configuration
Valence electrons: “the ones that can react” (located in the valence orbitals).
The other e-’s are called core electrons and don’t react.
2s2
3s2
4s2
5s2
6s2
7s2
Elements in a vertical row have the same number of valence electrons.

7. Atomic size affects many properties, both physical and chemical
Atomic sizes:

9. Smaller
Smaller
Li Be B C N O F Na
WHY? K

11. Ionization Energy:
The energy required to completely remove an e- from an atom in its gaseous state.
Mg(g)  Mg e-
1st ionization energy
Mg1+(g)  Mg e-
2nd ionization energy
Question: Which of the above ionizations would have the highest ionization energy and why?

12. electron being lost:
1st nd rd th th th th

13. Increases
Increases

15. I.E. Overhead

16. Electron Affinites:
The energy change that occurs when an electron is added to a gaseous atom .
Cl(g) + e-  Cl-(g) E = -349 kJ/mol
What does the negative value mean?

17. Electron affinity values

18. What is meant by metallic character?

19. Common Oxidation states: note the vertical similarities.

20. The Halogen Family:
Br2(l)
Cl2(g)
I2(s)

21. Alkali Metal Family Li K Na