Exercise 2
Question 22
In terms of band theory, what is the difference
(i) Between a conductor and an insulator
(ii) Between a conductor and a semiconductor
(1) in a conductor the energy gap is either very small or there is overlapping between valence band & conduction band.In case of an insulator the energy gap between valence band & conduction band is very large.Due to which, when an electric field is applied to an insulator, the electrons cannot jump from valence band to conduction band,& hence poor or no conduction of electricity.
(2) In a conductor,the energy gap between valence band & conduction band is very small but in an semi conductor there is always a small energy gap between them.
