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

Explanation

The characteristic property of transition elements to show variable oxidation state arises out of incompletely filld d-orbital in such a way that their oxidation states differ by unity Ex: V(II), V(III), V(IV) and V(V). However, in non transition elements, teh oxidation states differ generally by two. In the r-block elements the lower oxidation states are favoured by higher member because of inert pair effect while in d-block, higher oxidation states is favoured by higher members of the group. Ex. Mo(VI), W(VI) are more stable than Cr(VI). Thus, Cr(VI) act as good oxidizing agent in acidic medium while `MoO_(3) and WO_(3)` are not