Question

Use Hund's rule to derive the electronic configuration of Ce3+ ion and calculate its magnetic moment on the basis of 'spin-only' formula.

Answer 1

Ce: $1s^22s^22p^63s^23p^63d^{10}4s^24p^65s^25p^64f^15d^16s^2$
Magnetic moment can be calculated as:
$\mu=\sqrt{n(n+2)}$
Where,
n = number of unpaired electrons
The electronic configuration of $Ce^{3+}$ : $1s^22s^22p^63s^23p^63d^{10}4s^24p^65s^25p^64f^1$
In $Ce^{3+}$ n = 1
∴ ÃΖÂ1/4=1(1+2)-----