Chapter 29.1, Problem 21SSC

To determine

The usefulness of silicon dioxide as an insulator or a conductor.

Explanation of Solution

Introduction:

The valence band contains electrons in the valence shell which are not free to move. When energy is supplied, the electrons in the valence band move to conduction band in which they are free to move. The amount of energy required depends on the type of material.

The band gap for insulators is very wide starting at approximately For conductors the valence band and conduction band overlap. The band gap for silicon dioxide is which is very high for electrons to cross. Hence, silicon dioxide can be used as an electric insulator.

Conclusion:

Silicon dioxide can be used as an electric insulator.