Question

The energy gap between the conduction band and valence band is of the order of $0.07eV$. It is a/an

• A. insulator
• B. conductor
• C. semiconductor
• D. alloy

Answer 1

The correct option is B

conductor

The explanation for the correct option:

Conductor

1. An energy gap is a region of energy in a solid where there are no electron states or a region of energy where the density of states disappears.
2. After obtaining a little energy, electrons may migrate easily from the valence band to the conduction band due to the tiny gap.
3. In conductors, a valance band and a conduction band overlap as they have almost zero energy gap.
4. $0.07eV$ is the approximately nearest to zero.
5. Thus, it is a conductor having the energy gap between the conduction band and valence band is of the order of $0.07eV$.

The explanation for the incorrect options:

A: Insulator

1. About $15\left(eV\right)$ electron volts are needed to fill the energy gap in an insulator.
2. Because they are trapped between the atoms, the electrons in the valence band are unable to migrate.

C: Semiconductor

1. The term semiconductor refers to a class of materials that exhibit electrical conductivity that is between that of an insulator, such as glass, and a metal, such as copper, gold, etc.
2. Their energy gap is under $4eV$. (about $1eV$)

D: Alloys

1. There is no energy gap in alloys. Therefore, the option is incorrect.

Hence, option B is the correct answer.