question_answer

The spin only magnetic moment of \[F{{e}^{2+}}\] ion (in BM) is approximately

A)  4                                            

B)  7

C)  5                                            

D)  6

Correct Answer: C

Solution :

\[F{{e}^{2+}}-[Ar]\,\,3{{d}^{6}}\] It has 4 unpaired electrons \[\therefore \]  \[\mu =\sqrt{n\,\,(n+2)}\]                 \[=\sqrt{4\,(4+2)}\]                 \[=\sqrt{24}\]        \[\mu =4.89\,BM\approx 5\,BM\]