Summary of Quantum numbers of electrons in atoms Name Symbol Allowed Values Property Principal (Shell) n Positive integers (1, 2, 3, etc.) Orbital size and energy level Orbital shape (subshell) l Integers from 0 to (n-1) Orbital shape (l values 0, 1,2 and 3 correspond to s, p, d and f orbitals) Magnetic ml Integers from –l to +l Orbital orientation Spin ms +1/2 or -1/2 Spin orientation

Value of n Value of l Value of ml Subshell Number of orbitals (# of e- pairs) Total number of electrons in subshell 1 2 3 +1, 0, -1 3p 6 4

For an atom of oxygen, show possible quantum numbers for all eight electrons ml ms 1s1 1 1/2 1s2 2s1 2s2 2px1 2py1 2pz1 2px2

Using the Quantum Model

Energy Level Diagrams Used to show relative energies of electrons

Electron Configuration Provide the same information as the energy level diagrams List in order of increasing energy of the orbitals Shorthand: use the previous noble gas (lists only the outer shell electrons)

2p4 Example Oxygen: 1s22s22p4 Number of electrons in the orbital Principal quantum number orbital

Periodic Table