Question

Electronic configuration of oxygen is 2P4. Determine the ground state using LS coupling.​

Answer 1

Answer:

Give the electronic configuration for the Boron atom (Z = 5). Then enumerate the allowed term symbols 2S+1LJ for the ground state from the point of view of angular momenta alone.

Solution:

Concepts:

The energy levels of multi-electron atoms

Reasoning:

We use the Pauli exclusion principle and the rules for adding angular momentum to find the allowed terms 2S+1L.

Details of the calculation:

The electronic configuration is (1s)2, (2s)2, 2p.

The 1s and 2s shells are full and have L = 0, S = 0, J = 0.

The one 2p electron determines S, L, and J.

s = ½, l = 1, j = ½, 3/2.

The allowed terms are 2P½ and 2P3/2.

Hund's rule: The component with the smallest value of J (J = ½) has the lowest energy.