Give example and suggest reasons for the following features of the transition metal chemistry.
(a) The lowest oxide of transition metal is basic, the highest is acidic.
(b) A transition metal exhibits higher oxidation states in oxides and fluorides.
(c) The highest oxidation state is exhibited in oxoanions of a metal.

Explanation

(a) In lowest oxidation state ionic bonds are formed. As such metals in their lowest oxidation state form ionic oxides which are soluble in water, giving `OH^(-)` ions, thus forın basic oxides. While in highest oxidation states, transition metals show non-metallic character. Covalent bonds are formed and oxidcs get hydrolysed by water forming acids.
(b) Oxygen and fluorine being small in size are strong oxidizing agents and can provide energy for excitation of electrons. Thus transition metal exhibits higher oxidation states in oxides and fluorides.
(c) In oxoanions, the highest oxidation state is exhibited because oxygen is a strong oxidizing agent. For example, highest oxidation state in Mn is +7 in `MnO_(4)^(-)` and that of Cr is +6 in `CrO_(4)^(2-)`.