\({ }_{23} \mathrm{~V}^{-2} \Rightarrow[\mathrm{Ar}] 3 \mathrm{~d}^3\)
\({ }_{25} \mathrm{Mn}^{+2} \Rightarrow[\mathrm{Ar}] 3 \mathrm{~d}^5\)
\({ }_{26} \mathrm{Fe}^{+2} \Rightarrow[\mathrm{Ar}] 3 \mathrm{~d}^0\)