Question:
The correct electronic configuration and spinonly magnetic moment $(B M)$ of $G d^{3+}(Z=64)$, respectively, are
Correct Option: , 2
Solution:
Electronic configuration of $\mathrm{Gd}^{3+}$ is
${ }_{64} \mathrm{Gd}^{3+}=[\mathrm{Xe}] 4 \mathrm{f}^{7}$
$\mathrm{Gd}^{3+}$ having 7 unpaired electrons.
Magnetic moment $(\mu)=\sqrt{\mathrm{n}(\mathrm{n}+2)}$ B.M.
$\mu=\sqrt{7(7+2)}$ B.M.
$=7.9$ B.M.
$\mathrm{n} \Rightarrow$ Number of unpaired electrons.