Question

The halides of transition elements become more covalent with increasing oxidation state of the metal. Why?

Answer 1

We know that, with increasing oxidation state, the size of the transition metal cations decreases and so the polarising power increases.
And according to , Fajan's rule, smaller the size of cation greater is the covalent character and so the halids of transition metals becomes more covalent with increasing oxidation state.

Answer 2

Hey !!

As the oxidation state increases, size of the ion of the transition element decreases. As per ''Fajan's rule'' as the size of metal ion decreases, covalent character of the bond formed increases.

Good luck !!