Question

Which of the following ions is paramagnetic?

• A. $S{c}^{++}$
• B. $C{u}^{++}$
• C. $Z{n}^{++}$
• D. $N{i}^{++}$

Answer 1

Answer: (D)

Elements or ions containing unpaired electrons are paramagnetic.
${}_{28}Ni=\left[Ar\right]3d^{8}4s^2;N{i}^{2+}=\left[Ar\right]3d^{8}4s^0$

Because $N{i}^{2+}$ ions have 2 unpaired electrons in $3d$ subshell therefore it is paramagnetic.