Use Hund's rule to derive the electronic configuration of `Ce^(3+)` ion, and calculatel its magntic moment on the basis of spin-only formula.

Answer

1.73

Explanation

The electronic configuration of `Ce^(3+)` (atomic no. of Ce=58) is
`1s^(2) 2s^(2) 2p^(6) 3s^(2) 3p^(6) 4s^(2) 3d^(10) 4p^(6) 5s^(2) 4d^(10) 5p^(6) 6s^(1)`
There is only one unpaired electron in `Ce^(3+)` ions. The spin-only formula for calculating the magnetic moment is
`mu = sqrt(n(n+2))` BM
where n is the number of unpiared electrons in the species Here,n=1,
So, `mu = sqrt(1 xx 3)` BM =1.73 BM