Question

Sn, c, Si and Ge are all group 14 elements .Yet, Sn is a conductor ,C is an insulator while Si and Ge are semiconductors. Why?

Answer 1

Although all the above-given elements belong to the Group 14 of the periodic table, a few elements are conductors, a few as semiconductors, and a few as insulators.

The energy gap in between the valence band and the conduction band of an element determines its conduction level.

The energy gap is zero in the conductors because there is no energy gap in between the valence band and the conduction band. The energy gap for Sn is 0 eV. So, it acts as a conductor.

Similarly, the energy gap for semi-conductors is moderate and it is large for the insulators.

Si and Ge have an energy gap of 1.1 eV and 0.7 eV respectively, so they act as semiconductors.

C has an energy gap of 5.4 eV so it acts as an insulator.