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

Answer

The variability in oxidation state of trasnsition is due to the incomplete filling of d-orbitals in such a way that their oxidation states differ from each other by unity e.g., Fe^(2+)` and `Fe^(3+)` Cu^(+) and Cu^(2+)` etc. In case of non -transition elements , the oxidation state differ by units of two ,e.g., `pb^(2+)`, and `Sn^(2+)` and `Sn^(4+)` etc. Moreover , in transition elements ,t he higher oxidation states are more stable for heavier elements in a group. For example, in group6 `Mp(VI)` and `W(VI)` are more stable than `Cr(VI)` . In p-block elements , the lower oxidation state are more stable for heavier members due to inert pair effect,e.g., in group 14 , `pb(II) is more stable than pb(IV)`