Question

Which shows maximum magnetic moment among the bivalent ions of the first transition series ?

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

Answer 1

The correct option is D $M{n}^{2+}$

As we know,
Magnetic moment $\mu =\sqrt{n(n+2)}$, n is no of unpaired electron.

So higher the number of unpaired electrons, the higher is the magnetic moment.

$F{e}^{2+}\to d^6\to$ 4 unpaired electrons

$C{o}^{2+}\to d^7\to$ 3 unpaired electrons

$N{i}^{2+}\to d^8\to$ 2 unpaired electrons

$M{n}^{2+}\to d^5\to$ 5 unpaired electrons so it will have the highest magnetic moment.