\(\mathrm{Co}^{+3}=3 \mathrm{d}^{6} 4 \mathrm{s}^{0} 4 \mathrm{p}^{0}\)
\(\because\) in presence of strong field ligand, pairing of electrons occurs so in this complex no unpaired electron is present and
it is low spin complex.
(પ.ક્ર.: $Mn\, = 25, Co\, = 27, Ni\, = 28, Zn\, = 30$)