1. Warm Up9-17-15 1. 1. Which element has this electron configuration 1s 2 2s 2 2p 4 2. 2. How many electrons are in the s orbitals for Mg? 3. 3. How many electrons can the d orbital hold? 4. 4. Write the electron configuration for Zr Homework Sept 18 - Online HW Sept 23 - Test Unit 2 Sept 23 - Notebook check Agenda Turn in flame lab Notes Unit 2-6 Test review WS Online HW

2. Unit 2-6 Short Hand Electron Configuration

3. Orbital Filling Pauli Exclusion Principle Pauli Exclusion Principle No more than two electrons can be in the same orbital No more than two electrons can be in the same orbital Aufbau Principle Aufbau Principle Electrons fill orbitals that have the lowest energy first Electrons fill orbitals that have the lowest energy first Hund’s Rule Hund’s Rule Orbitals of the same quantum number are occupied by one electron before any pairing occurs Orbitals of the same quantum number are occupied by one electron before any pairing occurs

4. Orbital Filling Examples

5. E. Configuration (Short Hand)

6. Using the previous noble gas as a base Using the previous noble gas as a base Sulfur = Ne as a base = Short hand= 1s 2 2s 2 2p 6 3s 2 3p 4 1s 2 2s 2 2p 6 [Ne] 3s 2 3p 4 E. Configuration Short Hand Notation

7. Electron Configuration Exceptions: Exceptions: Cu = [Ar] 3d 10 4s 1 Cr = [Ar] 3d 5 4s 1

8. Check for understanding: Check for understanding: Write the short hand notation for O, Mg, Zn Write the short hand notation for O, Mg, Zn

9. Assignments WS Unit 2 test review due next class WS Unit 2 test review due next class Online HW due Friday Online HW due Friday https://quest.cns.utexas.edu/ Notebook check Unit 2 due next week Notebook check Unit 2 due next week 6 days of notes 6 days of notes Unit 2-1 till 2-6 Unit 2-1 till 2-6 30 points total 30 points total