Carbon , silicon and germanium have four valence electrons each . At room temperature which one of the following statements is most appropriate ?

Options

A. The number of free conductor electrons is negligibly small in all the three
B. The number of free electrons for conduction is significant in all the three.
C. The number of free electrons for conduction is significant only in Si and Ge but very small in C
D. The number of free conduction electrons is significant in C but small in Si and Ge

Answer

C

Explanation

Carbon is an insulator while Si and Ge arc semiconductors. The band gap is maximum for carbon, less for silicon and least for Ge.
`therefore` C has very small number of free electrons.