Question

Choose the correct statement. In case of insulators,

• A. conduction band is partially filled and valence band is partially empty
• B. conduction band and valence band overlap each other
• C. conduction band is empty
• D. there is no gap between conduction and valence band

Hint:

Large energy gap between valence and conduction bands implies insulating behaviour.

Answer 1

The Correct Option is C

Step 1: Band structure of solids.
In solids, electrical conductivity depends on the distribution of electrons in the valence band and conduction band.
Step 2: Behaviour of insulators.
In insulators, the valence band is completely filled and the conduction band is completely empty due to a large energy gap between them.
Step 3: Elimination of incorrect options.
Options (A) and (B) correspond to conductors, while option (D) is incorrect because insulators have a large forbidden energy gap.
Step 4: Conclusion.
Hence, in insulators, the conduction band is empty.