Which of the following statements are true about metals ?
(a) Valence band overlaps with conduction band
(b) The gap between valence band and conduction band is negligible
(c) The gap between valence band and conduction band connot be determined
(d) Valence band may remain partially filled
The answers: (a), (b), and (d).
Option (a), (b) and (d) are true, option (c) can be correctly stated as the gap between valence band and conduction band can be determined. The gap between valence band and conduction band decide the conductivity of material.