Chemistry - Complete d-block Question with Solution | TestHub

${\mathrm{Cu}}^{2+}:\left[\mathrm{Ar}\right]3{ \mathrm{d}}^{9}4{ \mathrm{s}}^0$
${\mathrm{Cr}}^{3+}:\left[\mathrm{Ar}\right]3{ \mathrm{d}}^{3}4{ \mathrm{s}}^0$
${\mathrm{Sc}}^{+}:\left[\mathrm{Ar}\right]3{ \mathrm{d}}^{1}4{ \mathrm{s}}^1$

All are coloured and paramagnetic due to presence of unpaired electrons.