JEE Main 2022 — D And F Block Elements Question with Solution

${\mathrm{Sc}}^{+3}$ and ${\mathrm{Zn}}^{+2}$ are colourless as they contain no unpaired electron. Whereas the transition metal ions ${\mathrm{Cu}}^{+2},{\mathrm{Ti}}^{+3},{\mathrm{V}}^{+2}$ and ${\mathrm{Mn}}^{+2}$ are coloured as they contain unpaired electrons.

The unpaired electron from lower energy $d$ orbital gets excited to a higher energy $d$ orbital on absorbing light of frequency which lies in visible region. The colour complementary to light absorbed is observed.