1. EXAM #3 MONDAY, NOVEMBER 9 TH Resources posted on course web site: Study Guide Practice Problems (Study group problems and answer key) Video Review Today:Periodic Properties November 6, 2009

2. Electron Configurations and the Periodic Table Chromium and copper are anomalies Cr Cu

3. Periodic Trends How does the electron configuration lead to the properties of an element? Basic Properties  Size  Ionization Energy  Electron Affinity  Ion Size (electron configuration of ions) Keep in mind Coulomb’s Law (force between charges):

4. Trends in Orbital Energies

6. Why do energies decrease moving left to right? Overall attraction of nucleus for electrons determines energies and size  Less attraction  higher energy  Attraction dependent on distance and charge  Effective nuclear charge (Z*) Z*= Z – S Z=nuclear charge S=shielding

7. What happens to the force of attraction between the outermost electrons and the protons in the nucleus as you go down a group? … as you go across a period? Atomic Size

8. Which atom is the smallest? 1. H 2. He 3. Cs 4. Rn

9. Which atom is the largest? 1. K 2. Ca 3. Rb 4. Sr

12. Electron Configurations of Cations

13. Transition Metal Cations: Lose s electrons first

14. Ion Size