Which is more stables ? `Fe^(3+) ` or `Fe^(2+)` - explain .

Explanation

`Fe(Z=26)" " Fe to Fe^(2+)+2e^(-)`
`Fe to Fe^(3+) +3e^(-)`
`Fe^(2+)` [Number of electrons 24]
Electronic configuration `=[Ar]3d^(6)`
`Fe^(3+)` [Number of electrons 23]
Electronic configuration `=[Ar]3d^(5)`
Among `Fe^(3+) and Fe^(2+), Fe^(3+)` is more stable due to half filled d-orbital. This can be explained by Aufbau principle. Half filled and completely filled d-orbitals are more stable than partially filled d-orbitals. So `Fe^(3+)` is more stable than `Fe^(2+)`.