NEETChemistrySolid State
Why do some substances behave as insulators?
Options
- ABecause they have a large number of valence electrons.
- BBecause the gap between the valence band and the conduction band is small.
- CBecause the gap between the valence band and the conduction band is large.
- DBecause they are in the liquid state.
Correct answer
C. Because the gap between the valence band and the conduction band is large.
Step-by-step solution
Substances behave as insulators when the gap between the valence band and the conduction band (the band gap) is large, preventing electrons from jumping to the conduction band and resulting in very small conductivity.