Although in the p–block the lower oxidation states are favoured by the
heavier members (due to inert pair effect), the opposite is true in the
groups of d-block For example, in group 6, Mo(VI) and W(VI) are
found to be more stable than Cr(VI) Thus Cr(VI) in the form of dichromate
in acidic medium is a strong oxidising agent, whereas MoO3 and WO3
are not Low oxidation states are found when a complex compound has
ligands capable of p-acceptor character in addition to the s-bonding