Chemistry - Atomic Structure Question with Solution | TestHub

${\mathrm{Cr}}^{+2}=3{\mathrm{d}}^4$ 

n = number of unpaired electrons.

$\mathrm{\mu }=\sqrt{\mathrm{n}(\mathrm{n}+2)}\mathrm{ }\mathrm{B}.\mathrm{M}.\mathrm{ }=\sqrt{4\left(6\right)}=\sqrt{24}\mathrm{ }\mathrm{B}.\mathrm{M}.\mathrm{ }$

$=4.90\mathrm{B}.\mathrm{M}.$