1. Dr. Chin Chu River Dell Regional High School Unit 3 – Electron Configurations Part E: Electron Configurations

2. Four Quantum Numbers A.Principal Quantum Number (n) main energy level B. Orbital Quantum Number (l) shape of orbital (s, p, d, f) C. Magnetic Quantum Number (m) orientation of orbital about the nucleus D. Spin Quantum Number (s) indicates clockwise or counter-clockwise spin of the electron (+½ or –½) Erwin Schrodinger 1887-1961

7. 1s 2s 2p 3s 3p 3d 4s 4p 4d 4f 5s 5p 5d 5f 6s 6p 6d 6f 7s 7p 7d 7f

12. RULES TO REMEMBER: Electron occupies the lowest energy orbital that can receive it. Always start with 1s. Any given orbital can hold a maximum of 2 e -. Orbitals of equal energy are each occupied by one electron spinning in opposite directions before any orbital is occupied by a second electron.

13. Increasing energy 1s 2s 3s 4s 5s 6s 7s 2p 3p 4p 5p 6p 3d 4d 5d 7p 6d 4f 5f 1s 2s 2p 3s 3p 3d 4s 4p 4d 4f 5s 5p 5d 5f 6s 6p 6d 6f 7s 7p 7d 7f