Compare the stability of + 2 oxidation state of the elements of the first transition series.

Explanation

Element (+2 state) `""_(21)Sc^(2+) ""_(22)Ti^(2+)""_(23)V^(2+)""_(24)Cr^(2+)""_(25)Mn^(2+)`
Electronic configuration `3d^(1)3d^(2)3d^(3)3d^(4)3d^(5)`
In all the elements listed, the removal of two 4s. Electrons (in `Cr^(2+)`, i.e., from 4s and `"le"^(-)` from 3d), the 3d-orbitals get gradually occupied. Since, the number of empty d-orbitals decreases, or the number unpaired electrons in 3d-orbitals increases with increase in atomic number of cations, so the stability of the cations `(M^(2+))` increases from `Sc^(2+)" to "Mn^(2+)`