$\begin{array}{ll}
\text{Unpaired electron} \
\operatorname{Sc}[\mathrm{Ar}] 4 \mathrm{s}^2 3 \mathrm{d}^1 & 1 \
\mathrm{Cr}[\mathrm{Ar}] 4 \mathrm{s}^1 3 \mathrm{d}^5 & 6 \
\mathrm{V}[\mathrm{Ar}] 4 \mathrm{s}^2 3 \mathrm{d}^3 & 3 \
\mathrm{Ti}:[\mathrm{Ar}] 4 \mathrm{s}^2 3 \mathrm{d}^2 & 2 \
\mathrm{Mn}:[\mathrm{Ar}] 4 \mathrm{s}^2 3 \mathrm{d}^5 & 5
\end{array}$