Question

If the band-gap between valence band and conduction band in a material is $5.0eV$, then the material is a/an

• A. good conductor
• B. semiconductor
• C. superconductor
• D. insulator

Answer 1

Answer: (D)

The band gap in a conductor is Zero.

The band gap in semiconductor is nearly equal to $1eV$

For example : For silicon, band gap is $1.11eV$

Insulators generally have very large band gap and thus they do not allow the electrons to jump from valance band to conduction band.

The band gap in an insulator $\ge 5eV$

For example : Diamond has a band gap of $5.5eV$

Hence the above given material with band gap of $5.0eV$ must be an insulator.