The formula for calculating 'spin only' magnetic moment is
The formula for calculating 'spin only' magnetic moment is
$n(n+2)$
$\sqrt{n(n-2)}$
$\sqrt{n(n+2)}$
$n(n-2)$
Solution
The formula used to calculate the spin only magnetic moment can be written in two forms, the first based on the number of unpaired electrons $n$ and the second based on the total electron spin quantum number $s$. Since, for each unpaired electron, $n=1$ and $s=\frac{1}{2}$ then the two formulae are clearly related and the answer obtained must be identical
$
\mu_{\mathrm{so}}=\sqrt{n(n+2)} \mathrm{BM}=\sqrt{4 s(s+1)} \mathrm{BM}
$
Hence, the correct option is (3)