Question

Which of the following lanthanoid ions is diamagnetic?
(At nos. Ce = 58, Sm = 62, Eu = 63, Yb = 70)

• A. $S{m}^{2+}$
• B. $E{u}^{2+}$
• C. $Y{b}^{2+}$
• D. $C{e}^{2+}$

Answer 1

Answer: (C)

$\text{Yb}={\left[\text{Xe}\right]}^{54}4{\text{f}}^{14}5{\text{d}}^{0}6{\text{s}}^2$
$Y{b}^{2+}=[Xe]4f^{14}$
As n = 0 so diamagnetic.
As in rest other there are unpaired electron/s so they are paramagnetic.