(પ. ક્ર.: $Sc = 21 , Ti = 22, V = 23, Zn = 30$)
The electronic configuration of the given elements is
$S{c^{3 + }}(18)\, = \,1{s^2}\,2{s^2}\,2{p^6}\,3{s^2}\,3{p^6}\,3{d^0}\,4{s^0}$ no unpaired $e^-$
$T{i^{4 + }}(18)\, = \,1{s^2}\,2{s^2}\,2{p^6}\,3{s^2}\,3{p^6}\,3{d^0}\,4{s^0}$ no unpaired $e^-$
${V^{3 + }}(18)\, = \,1{s^2}\,2{s^2}\,2{p^6}\,3{s^2}\,3{p^6}\,3{d^2}\,4{s^0}$ - Two unpaired $e^-$.
$Z{n^{2 + }}(28)\, = \,1{s^2}\,2{s^2}\,2{p^6}\,3{s^2}\,3{p^6}\,3{d^{10}}\,4{s^0}$ no unpaired $e^-$
hence $[V(NH_3)_6]^{3+}$ will moost likely absorb visible light.
(પરમાણુ ક્રમાંક : $Zn = 30$, $Cr = 24$, $Co = 27$, $Ni = 28$)