CBSE Class 12-science Answered

.As per the band theory in the conductor there is as an overlap of the valence band and the conduction band so that a fraction of the valence electrons can move through the material and in insulator in terms of the band theory of solids this implies that there is a large forbidden gap between the energies of the valence electrons and the energy at which the electrons cannot move freely through the material .(Draw diagram of two bands in conductor overlapping and in insulator there gap is more and label the band as valence & conduction band.