1. Atomic Radius Across Period Atomic size DECREASES Because nuclear charge (# p + ) increases, as e - are added to same n, pulls e- in tighter Down Group Atomic size INCREASES Because more n (shells), more shielding, e - further away from nucleus
2. Electronegativity The ability to attract e - Across Period EN INCREASES Because nuclear charge (# p + ) increases Down Group EN DECREASES Because more n, more shielding, e - further away from nucleus
3. Ionization Potential/Energy IE: Energy required to remove e - Higher the IE: more difficult to remove e - Across Period IE INCREASES* * with decrease @ each subshell Why? Down Group IE DECREASES Why?
4. Ionic Radius Ion- Charged atom Cation Positive (+) ion (neutral atom looses e - ) Anion Negative (-) ion (neutral atom gains e - )