Question

Explain insulator and semiconductor on the basis of conduction of electricity.

Answer 1

Insulators:
They are bad conductors of heat and electricity. The space between valence band and conduction band is relatively more . Hence, more energy is required to promote electrons from valence band to conduction band. This amount of energy is not available. Electrons remain in valence band.They cannot move freely. Examples of insulators include glass, rubber, polythene, plastic, wood and diamond.
Semiconductors:
They are poor conductors of heat and electricity. The space between valence band and conduction band is small . Hence, slight heating promotes electrons from valence band to conduction band. Excited electrons in empty conduction band can move freely. Examples of insulators include silicon and germanium.