Question

The following terms arise from a d8 electron configuration: 1S, 1D, 1G, 3P, 3F Use the first two of Hund's rules to properly order these terms according to energy. Then, determine the term symbols arising from each term, and use the third Hund's rule to complete the energy ordering.

Answer 1

According Hund's first rule the term greater spin multiplicity has the lowest energy.

So 3F and 3P have lower energy than remaining three terms.

Second rule.

The term greater L value will have lower energy

L values for terms

for 3F , L= 3

For 3P, L =1

For 1G, L= 4

For, 1D, L = 2

For, 1S, L = 0

From above two rules order of energries of terms is

Lowest to highest

3F < 3P< 1G< 1D< 1S

Including J values order of terms

Lowest to highest

3F4 < 3F3< 3F2<3P2<3P1<3P0<1G4<1D2<1S0