Manganese ($Mn$) has the electronic configuration $[Ar]3d^{5}4s^2$.

• It has the maximum number of unpaired electrons in the $3d$ series. It can lose or share all $7$ valence electrons ($5$ from $3d$ and $2$ from $4s$).
• Maximum State: $+7$, which is seen in the Permanganate ion ($Mn{O}_4^{-}$).
• This is the highest oxidation state for any element in the first transition ($3d$) series.