Question

In insulators, there is a _____ gap between valence band and conduction band.

Answer 1

In insulators the electrons in the valence band are separated by a large gap from the conduction band, in conductors like metals the valence band overlaps the conduction band, and in semiconductors there is a small enough gap between the valence and conduction bands that thermal or other excitations can bridge the gap.

Answer 2

Narrow, I guess...

Hooe it finds its destination