Using the Hund rules, find the magnetic moment of the ground state of the atom whose open subshell is half-filled with five electrons.

Explanation

We have `5d` electrons in the only unfilled shell. Then `S=(5)/(2)`. Maximum value of `L` consistent with Pauli's principle is `L=0`. Then `J=(5)/(2)`.
So by Lande's formula
`g=1+((5)/(2)(7/2)+(5)/(2)(7/2)-0)/(2(5)/(2)((7)/(2)))=2`
Thus `mu=gsqrt(J(J+1))mu_(B)=2(sqrt(35))/(2)mu_(B)=2sqrt(35)mu_(B)`.
The ground state is `.^(6)S_(5//2)`.