The conduction band of a solid is partially filled at 0 K.will it be a conductor, a semiconductor or an insulator?

Out of the ionic, covalent and metallic and van der Waal's solids, which will be widely used to produce a conductor, semiconductor and insulator?

The main distinction between conductors, semiconductors and insulators is concerned with

Compare and explain the temperature dependence of resistivity in case of a conductor, a semiconductor and insulator with proper examples.

Explain formation of energy band in solids. Distinguish between conductors, extrinsic and intrinsic semi-conductors and insulators on the basis of band theory.