Question

The ion of least magnetic moment among the following is

• A. $T{i}^{3+}$
• B. $N{i}^{2+}$
• C. $C{o}^{2+}$
• D. $M{n}^{2+}$

Answer 1

Answer: (A)

Magnetic moment depends upon the number of unpaired electrons.
Lower the number of unpaired electrons, least is the magnetic moment.
$T{i}^{3+}=[Ar]3d^{1}4s^0$ (One unpaired electron)
$N{i}^{2+}=[Ar]3d^8,4s^0$ (Two unpaired electrons)
$C{o}^{2+}=[Ar]3d^7,4s^0$ (Three unpaired electrons)
$M{n}^{2+}=[Ar],3d^5,4s^0$ (Five unpaired electrons)
Thus, $T{i}^{3+}$, due to the presence of least number of unpaired electrons, has the least magnetic moment, among the given ions.