Among given metals, Cr has maximum IE2 because Second electron is removed from stable configuration 3d5 Cr+:[Ar]3 d54 s0 ∴ No of unpaired e−in Cr+is 5,n=5 $\begin{aligned}
\text { So, Magnetic moment } & =\sqrt{\mathrm{n}(\mathrm{n}+2)} \text { B.M } \
& =\sqrt{5(5+2)}=5.92 \quad \mathrm{BM} \approx 6
\end{aligned}$