1. II. Quantum Theory

2. A. Review of Atomic Theory Thomson Discovered the electrons Bohr Determined electrons travel around the nucleus according to energy; electrons with lower energy are closer to the nucleus Quantum Mechanical Model or Electrons Cloud Model Electrons orbit the nucleus in “clouds”; high probability of finding them somewhere along these paths

3. B. Electron Configuration Electron can jump multiple levels: 1 energy level (red light) 2 energy levels (green light) 3 energy levels (blue light) 4 energy levels (violet light)

4. B. Electron Configuration Cont. Electrons orbit in specific energy levels. There are seven energy levels Lowest energy level = smallest and the closest to the nucleus Each energy level has a specific, limited number of electrons

5. C. Energy Levels, Sublevels, & Orbitals The lowest energy level is n = 1 On the periodic table, each period (horizontal row) is an energy level

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7. C. Energy Levels, Sublevels, & Orbitals Each energy level has energy sublevels: s, p, d, f Each energy sublevel has different number of orbitals Orbitals: 3-D clouds where electrons are found 90% of the time Each orbital can hold 2 electrons

8. s sublevel = 1 orbital (2 electrons) p sublevel = 3 orbitals (6 electrons) d sublevel = 5 orbitals (10 electrons) f sublevel = 7 orbitals (14 electrons) C. Energy Levels, Sublevels, & Orbitals

11. ENERGY LEVELS Sublevels (s, p, d, f) Orbitals (1, 3, 5, 7)

12. Energy Level (n) Sublevels# orbitalsMax # e - 1s12 2spsp 1313 2 6 (8 total) 3spdspd 135135 2 6 10 (18 total) 4spdfspdf 13571357 2 6 10 14 (32 total)

13. III. Electron Configuration

14. A. Electron Configuration Unabbreviated method for describing the arrangement of electrons Example: Helium (2 electrons) Helium: 1s 2 Energy Level Sublevel # electrons

15. C. Energy Levels, Sublevels, & Orbitals

16. A. Electron Configuration Example: Neon (10 electrons) Neon: 1s 2 2s 2 2p 6

17. A. Electron Configuration Example: Neon: 1s 2 2s 2 2p 6

18. Tips to Remembering Electron Configuration Simply count, left to right, and know where s, p, d, and f block are on the periodic table

19. B. Noble Gas Configuration Abbreviated electron configuration Write full electron configuration for both Neon (Ne) and Argon (Ar) Neon: 1s 2 2s 2 2p 6 Argon:1s 2 2s 2 2p 6 3s 2 3p 6 Argon: [Ne] 3s 2 3p 6