`Fe^(2+)` has a greater tendency to attain the + 3 oxidation state as compared to `Mn^(2+)`. Give reason.

Explanation

`Mn^(2+)(3d^(5)4s^(0))overset(-e)rarr Mn^(3+)(3d^(4)4s^(0))`
`Fe^(2+)(3d^(6)4s^(0))overset(-e)rarr Fe^(3+)(3d^(5)4s^(0))`
`Mn^(2+)` has half-filled d-orbitals which is a highly stable configuration. Hence, it does not have a tendency to attain the + 3 state to form `Mn^(3+)`. On the other hand, `Fe^(3+)` ion, by losing an electron, forms half-filled `(3d^(5))` d-orbitals. Hence `Fe^(2+)` has a greater tendency to from `Fe^(3+)`.