1. IV. Electron Configuration Electrons in Atoms

2. A. General Rules zPauli Exclusion Principle yEach orbital can hold 2 electrons with opposite spins. y “Opposites Attract”

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

4. A. General Rules zMore on Aufbau zOrder Orbitals Fill

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

6. H 1e - zOrbital Diagram zElectron Configuration 1s 1 B. Notation 1s

7. He 2e - zOrbital Diagram zElectron Configuration 1s 2 B. Notation 1s

8. Li 3e - zOrbital Diagram zElectron Configuration 1s 2 2s 1 B. Notation 1s 2s

9. Be 4e - zOrbital Diagram zElectron Configuration 1s 2 2s 2 B. Notation 1s 2s

10. B 5e - zOrbital Diagram zElectron Configuration 1s 2 2s 2 2p 1 B. Notation 1s 2s 2p

11. C 6e - zOrbital Diagram zElectron Configuration 1s 2 2s 2 2p 2 B. Notation 1s 2s 2p

12. N 7e - zOrbital Diagram zElectron Configuration 1s 2 2s 2 2p 3 B. Notation 1s 2s 2p

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

14. F 9e - zOrbital Diagram zElectron Configuration 1s 2 2s 2 2p 5 B. Notation 1s 2s 2p

15. Ne 10e - zOrbital Diagram zElectron Configuration 1s 2 2s 2 2p 6 B. Notation 1s 2s 2p

16. 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  Longhand Configuration

17. B. Notation zPractice with Electron Configuration Worksheet

18. © 1998 by Harcourt Brace & Company ns np (n-1)d (n-2)f n=1 n=2 n=3 n=4 n=5 n=6 n=7 C. Periodic Patterns

19. zPeriod # yenergy level (subtract for d & f) zColumn within sublevel block y# of e - in sublevel

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

21. 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.

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

23. C. Periodic Patterns zPeriodic Patterns Activity

24. zMost stable = Full energy level  Full sublevel (s, p, d, f) zHalf-full sublevel D. Stability

25. 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

26. 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

27. zIon Formation yAtoms gain or lose electrons to become more stable. yIsoelectronic with the Noble Gases.

28. O 2- 10e - 1s 2 2s 2 2p 6 D. Stability zIon Electron Configuration yWrite the e - config for the closest Noble Gas  EX: Oxygen ion  O 2-  Ne

29. D. Stability zPractice with Stability & Electron Configuration Worksheet