To what extant do the electronic configurations decide the stability of oxidation states in the first series of the transition elements ? Illustrate your answer with examples.

Explanation

In a transition series, the stability of an oxidation state of a particular element is determined largey by the electronic configuration of that oxidation state. The oxidation states which lead to noble gas configuration, or exactly half - filled or completely filled d - subshell, are exceptionally stable. Thus `Sc^(3+), Mn^(2+)` and `Zn^(2+)` ions are highly stable.
`Sc (Z = 21) : [Ar]3d^(1)4s^(2), Sc^(3+):[Ar]`
`Mn(Z=25):[Ar]3d^(5)4s^(2), Mn^(2+):[Ar]3d^(5)`
`Zn(Z=30):[Ar]3d^(10)4s^(2), Zn^(2+)"[Ar]3d^(10)`