1. EXAM #3 MONDAY, NOVEMBER 9 TH (Chapters 6 and 7) Bring a Periodic Table to class Manners reminder Today: Finish Chapter 7 Orbital filling Periodic Properties November 4, 2009

2. Rules for filling orbitals 1. Pauli Exclusion Principle No two electrons can have the same 4 quantum numbers An orbital has a maximum of 2 electrons of opposite spin 2. Aufbau/Build-up Principle Lower energy levels fill before higher energy levels 3. Hund’s Rule Electrons only pair after all orbitals at an energy level have 1 electron 4. Madelung’s Rule Orbitals fill in the order of the value of n + l

3. Madelung’s Rule= Orbital Filling Order

4. Three Types of Notation Electron Configuration Notations Orbital Box Notation Spectroscopic (spdf) Notation List subshells and how many electrons each contains For Sodium: 1s 2 2s 2 2p 6 3s 1 Noble Gas Notation Use next lowest Noble Gas to represent core List outer shells as in spectroscopic notation For Sodium: [Ne]3s 1 where [Ne]=1s 2 2s 2 2p 6

5. Electron Configurations and the Periodic Table n value increases as you move down (Li, Na, K) Li Na K K

6. Electron Configurations and the Periodic Table Periodic Blocks & Hund’s Rule (using the p block) Sc O O C C N N

7. Electron Configurations and the Periodic Table Using periodic blocks: everything is filled up to the bloakc you are in; count over to determine “how filled” the final orbital is

8. Electron Configurations and the Periodic Table

9. What is the electron configuration for Al? 1. 1s 2 2s 2 2p 6 3s 1 2. 1s 2 2s 2 2p 6 3s 2 3p 1 3. 1s 2 2s 2 2p 6 3s 2 3p 2 4. 1s 2 2s 2 2p 1

10. Which element has the ground state electron configuration 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 2 ? 1. K 2. Ca 3. Ti 4. Mn 5. Fe

11. Which is the correct Noble Gas electron configuration for the element Zinc? 1. [Ne]3s 2 3p 6 4s 2 3d 10 2. [Ne] 3s 2 3p 6 3. [Ar] 3s 2 3p 6 4s 2 3d 10 4. [Ar] 3d 10 4s 1 5. [Ar]3d 10 4s 2

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