A. The energy band of valence electrons is called Valence band B. The energy band of free electrons or loosely bound electrons is called conduction band.

……… electrons occupy the conduction band.

Assertion: If there is some gap between the conduction band and the valence band, electrons in the valence band all remain bound and no free electrons are available in the conduction band. Then the material is an insulator. Reason: Resistance of insulators is very low

Assertion: If there is some gap between the conduction band and the valence band, electrons in the valence band all remain bound and no free electrons are available in the conduction band. Then the material is an insulator. Reason: Resistance of insulators is very low

Compare valence band and conduction band.