Ionization energies of aluminum 577 1816 2744 11577 kJ 3p1 Ionization energies of aluminum loses c.s. 3s2 loses repulsions 3s1 loses c.s. 2p6

M0 + I.E. → M+ + 1e- IONIZATION ENERGY: The energy required to remove an electron from an isolated atom M0 + I.E. → M+ + 1e- The energy required to remove an electron from an isolated atom IONIZATION ENERGY:

repulsions hn C.S. Photoionization Generally Decreases e-► e-► e-► e-► Light Gaseous (isolated) atoms repulsions (photons) ammeter ions hn C.S. e-► ◄e- Generally Increases

Electron Affinity (generally) NM0 + 1e- → NM- + nrg Repulsions responsible for positive E.A. N (+7 kJ/mol) ---------2p---------- Generally becomes more negative (generally) NM0 + 1e- → NM- + nrg (The energy change associated with adding an electron to an isolated atom) Electron Affinity

Determining the Atomic Radius of a Nonmetal (Chlorine)

Inc. Zeff Inc. Dec. I.E. More Neg. Dec. E.A. Less Neg. Dec. (more protons) Inc. (Zeff▲) Zeff Dec. Inc. (Zeff▲) (C.S.) I.E. More Neg. Dec. E.A. (Zeff▲) (Zeff▼) Less Neg. Dec. Atomic Radius (Zeff▼) Inc. (Zeff▼)