Question

Following question is based on $Sc$ (Z$=$ 21).

Out of $S{c}^{3+},S{c}^{2+}$ and $S{c}^{+}$ paramagnetic as well coloured ions are:

• A. $S{c}^{+},S{c}^{2+}$
• B. $S{c}^{3+},S{c}^{+}$
• C. $S{c}^{2+},S{c}^{3+}$
• D. all being d-block element

Answer 1

The correct option is A $S{c}^{+},S{c}^{2+}$

$Sc:$ $\left[Ar\right]3d^{1}4s^2$ have one unpaired electron

$S{c}^{+}:\left[Ar\right]3d^{1}4s^1$ have two unpaired electron

$S{c}^{+2}:\left[Ar\right]3d^{1}4s^0$ have one unpaired electron

$S{c}^{3+}:\left[Ar\right]3d^{0}4s^0$ have zero unpaired electron

So species with unpaired electron will have paramagnetic as well as coloured ions.

Hence, the correct option is $A$