8.13 How is the variability in oxidation states of transition metals different from that of non-transition metals? Illustrate with examples.

In the case of transition elements, the variability in the oxidation state is due to the participation of (n-1) d orbitals and ns orbitals. 

The oxidation states differ by unity. Thus, V shows +2, +3, +4, and +5 oxidation states and Mn shows +2, +3, +4, +5, +6, and +7 oxidation states.

On the other hand, the variable oxidation states shown by some p block elements differ by two units. Thus, tin shows +2 and +4 oxidation states and indium shows +1 and +3 oxidation states.