Account for the following:

(a) The highest oxidation state of a metal is exhibited in its oxides or fluorides only.

(b) Transition metals form coloured compounds.

(c) Transition elements form interstitial compounds.

(a) Oxygen and Fluorine are the most electronegative elements of whole periodic table. So, they have the tendency to gain maximum electron and gets reduced to the maximum extent and thereby oxidising the metal to its highest possible oxidation state.

(b) The color of transition metals is mainly due to unpaired electrons and empty d orbital. When the unpaired electron on gaining energy jumps from a lower energy level to a high energy level, they absorb some amount of energy. And when they come back into lower energy level, they emit the energy in visible region. The color of corresponding wavelength to energy emitted can be seen.

(c) The crystal lattice of transition metals have vacant sites between them, which can be filled by small atoms like H,N,C. as these small atoms are trapped in the interstial sites (vacant) sites, transition metal can form interstitial compounds.