Which element from following does NOT exhibit spin only magnetic moment in +3 state?
Which element from following does NOT exhibit spin only magnetic moment in +3 state?
$\mathrm{Cr}$
V
$\mathrm{Ti}$
$\mathrm{Sc}$
Solution
The element that does not exhibit spin only magnetic moment in the +3 state is $\mathrm{Sc}$ (Scandium). This is because Sc loses all of its 3d electrons when it forms a +3 ion, leaving only its 4s electrons. Since there are no unpaired electrons in the 4s subshell, the $\mathrm{Sc}^{3+}$ ion has no spin magnetic moment. The other elements listed ($\mathrm{C}$, $\mathrm{Ti}$, and unknown element) all have partially filled d orbitals in their +3 state, which can lead to unpaired electrons and a spin magnetic moment.