Question

The spin only magnetic moment of $Mn^{+4}$ ion is nearly____

• A. $6 \,BM$
• B. $3\, BM$
• C. $5\, BM$
• D. $4\, BM$

Answer 1

Answer: (D)

$4\, BM$

Answer 2

The electronic configuration of $Mn$ is ${ }_{25} Mn =[ Ar ] 3 d^{5} 4 s^{2}$ $Mn ^{4+} =[ Ar ] 3 d^{3}$ Thus, three unpaired electrons are present. $\therefore$ Spin only magnetic moment, $\mu=\sqrt{n(n+2)}$ $\therefore$ $\therefore n=3$ $\therefore \mu=\sqrt{3(3+2)}$ $=\sqrt{15}=3.87$ $=4\, BM$