The outer electronic configurations of two transition metals are (i) `3d^(5)4s^(2)` and (ii) `3d^(6)4s^(2)` respectively. Based on this information predict the relative stability of +2 and +3 oxidation state of these metals. Which of the two exhibits larger number of oxidation states ?

Explanation

Metal with configuration `3d^(5)4s^(2)` will show oxidation state (+2) more readily because of greater stability of half-filled d-orbitals. Metal with configuration `3d^(6)4s^(2)` will be more stable in +3 oxidation state than +2 due because after losing two electrons the configuration of the metal ion will be `3d^(5)`, which is a stable configuration.