1. C. Johannesson IV. Electron Configuration (p. 105 - 116, 128 - 139) Ch. 4 - Electrons in Atoms

2. C. Johannesson A. General Rules zPauli Exclusion Principle yEach orbital can hold TWO electrons with opposite spins.

3. C. Johannesson A. General Rules zAufbau Principle yElectrons fill the lowest energy orbitals first. y“Lazy Tenant Rule”

4. C. Johannesson RIGHT WRONG A. General Rules zHund’s Rule yWithin a sublevel, place one e - per orbital before pairing them. y“Empty Bus Seat Rule”

5. C. Johannesson O 8e - zOrbital Diagram zElectron Configuration 1s 2 2s 2 2p 4 B. Notation 1s 2s 2p

6. C. Johannesson zShorthand Configuration S 16e - Valence Electrons Core Electrons S16e - [Ne] 3s 2 3p 4 1s 2 2s 2 2p 6 3s 2 3p 4 B. Notation zLonghand Configuration

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

8. C. Johannesson C. Periodic Patterns zPeriod # yenergy level (subtract for d & f) zA/B Group # ytotal # of valence e - zColumn within sublevel block y# of e - in sublevel

9. C. Johannesson s-block1st Period 1s 1 1st column of s-block C. Periodic Patterns zExample - Hydrogen

10. C. Johannesson C. Periodic Patterns zShorthand Configuration yCore e - : Go up one row and over to the Noble Gas. yValence e - : On the next row, fill in the # of e - in each sublevel.

11. C. Johannesson [Ar]4s 2 3d 10 4p 2 C. Periodic Patterns zExample - Germanium

12. C. Johannesson zFull energy level zFull sublevel (s, p, d, f) zHalf-full sublevel D. Stability

13. C. Johannesson zElectron Configuration Exceptions yCopper EXPECT :[Ar] 4s 2 3d 9 ACTUALLY :[Ar] 4s 1 3d 10 yCopper gains stability with a full d-sublevel. D. Stability

14. C. Johannesson zElectron Configuration Exceptions yChromium EXPECT :[Ar] 4s 2 3d 4 ACTUALLY :[Ar] 4s 1 3d 5 yChromium gains stability with a half-full d-sublevel. D. Stability

15. C. Johannesson D. Stability zIon Formation yAtoms gain or lose electrons to become more stable. yIsoelectronic with the Noble Gases.

16. C. Johannesson O 2- 10e - [He] 2s 2 2p 6 D. Stability zIon Electron Configuration yWrite the e - config for the closest Noble Gas yEX: Oxygen ion  O 2-  Ne