Chapter 29.1, Problem 19SSC

To determine

Whether a magnesium oxide material is a conductor, an insulator or a semiconductor if it has a forbidden gap of 8 eV.

Explanation of Solution

Introduction:

Solids are classified into three main types- conductor, semiconductor and insulators. The band gap of conductor, semiconductor and insulators is different.

The forbidden energy gap between conduction band and valance band decides whether the material is conductor, semiconductor or insulator.

For insulators, the lowest energy level for conduction band is 5 eV to 10 eV above the highest energy level of valence band. The magnesium material has forbidden gap of 8 eV, so it is an insulator.

Conclusion:

As magnesium material forbidden energy gap is more than 5 eV, so it is an insulating material.