1. Electron Configuration Electrons in Atoms

2. General Rules Pauli Exclusion Principle Each orbital can hold TWO electrons with opposite spins.

3. General Rules Aufbau Principle Electrons fill the lowest energy sublevels first. “Lazy Tenant Rule”

4. RIGHT WRONG General Rules Hund’s Rule Within a sublevel, place one e - per orbital before pairing them. “Empty Bus Seat Rule”

5. General Rules There are 4 types of orbitals: s can hold a maximum of 2 electrons p can hold a maximum of 6 electrons d can hold a maximum of 10 electrons f can hold a maximum of 14 electrons

6. © 1998 by Harcourt Brace & Company s p d (n-1) f (n-2) 12345671234567 6767 Periodic Patterns

8. s-block1st Period 1s 1 1st column of s-block Periodic Patterns Example - Hydrogen

9. O 8e - Orbital Diagram Electron Configuration 1s 2 2s 2 2p 4 Notation 1s 2s 2p

10. [Ar]4s 2 3d 10 4p 2 Periodic Patterns Example - Germanium

11. Shorthand Configuration S 16e - Valence Electrons Core Electrons S16e - [Ne] 3s 2 3p 4 1s 2 2s 2 2p 6 3s 2 3p 4 Notation Longhand Configuration

12. Practice Time Al Co As Sr Sn Pb 1s 2 2s 2 2p 6 3s 2 3p 1 or [Ne] 3s 2 3p 1 Give the longhand and shorthand configurations for the following: 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 7 or [Ar] 4s 2 3d 7 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 3 or [Ar] 4s 2 3d 10 4p 3 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 or [Kr] 5s 2 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 2 or [Kr] 5s 2 4d 10 5p 2 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 6s 2 4f 14 5d 10 6p 2 or [Xe] 6s 2 4f 14 5d 10 6p 2