Carbon, silicon and germanium have four valence electrons each. At room temperature which one of the following statements is most appropriate ?
The number of free electrons for conduction is significant only in $Si$ and $Ge$ but small in $C.$
The number of free conduction electrons is significant in $C$ but small in $Si$ and $Ge.$
The number of free conduction electrons is negligibly small in all the three.
The number of free electrons for conduction is significant in all the three
