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

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?

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.

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

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

Ionization Energy: The energy required to completely remove an e- from an atom in its gaseous state. Mg(g)  Mg1+ + e- 1st ionization energy Mg1+(g)  Mg2+ + e- 2nd ionization energy Question: Which of the above ionizations would have the highest ionization energy and why?

electron being lost: 1st 2nd 3rd 4th 5th 6th 7th

Increases Increases

I.E. Overhead

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?

Electron affinity values

What is meant by metallic character?

Common Oxidation states: note the vertical similarities.

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

Alkali Metal Family Li K Na