1. Quantum Numbers Each electron in an atom has a unique set of 4 quantum numbers which describe it.  Principal quantum number  Angular momentum quantum number  Magnetic quantum number  Spin quantum number

2. Pauli Exclusion Principle No two electrons in an atom can have the same four quantum numbers. Wolfgang Pauli

3. Spin Quantum Number Spin quantum number denotes the behavior (direction of spin) of an electron within a magnetic field. Possibilities for electron spin:

4. Orbital filling table

5. Electron configuration of the elements of the first three series

6. [He]2s 2 p 6 ____ ____ ____ ____ ____ 1s 2s 2p 1s 2 2s 2 p 6 Neon [He]2s 2 p 5 ____ ____ ____ ____ ____ 1s 2s 2p 1s 2 2s 2 p 5 Fluorine [He]2s 2 p 4 ____ ____ ____ ____ ____ 1s 2s 2p 1s 2 2s 2 p 4 Oxygen [He]2s 2 p 3 ____ ____ ____ ____ ____ 1s 2s 2p 1s 2 2s 2 p 3 Nitrogen [He]2s 2 p 2 ____ ____ ____ ____ ____ 1s 2s 2p 1s 2 2s 2 p 2 Carbon [He]2s 2 p 1 ____ ____ ____ ____ ____ 1s 2s 2p 1s 2 2s 2 p 1 Boron [He]2s 2 ____ ____ ____ ____ ____ 1s 2s 2p 1s 2 2s 2 Beryllium [He]2s 1 ____ ____ ____ ____ ____ 1s 2s 2p 1s 2 2s 1 Lithium Noble gas notation Orbital notationConfiguration notation Element

7. Irregular confirmations of Cr and Cu Chromium steals a 4s electron to half fill its 3d sublevel Copper steals a 4s electron to FILL its 3d sublevel