[" Example "14.1C," Si and Ge have same lattice structure.Why is "C],[" insulator while Si and Ge intrinsic semiconductors? "]

C,Si and Ge have the same lattice structure. Why is C insulator while Si and Ge intrinsic semiconductor.

C, Si and Ge have same lattice structure . Why is C an insulator while Si and Ge are intrinsic semiconductors ?

Sn, Si and Ge have the same lattice structure . Why Sn is a conductor while Si and Ge are Semiconductor?

Why are Ge and Si semiconductors ?

Why do Ge and Si are semiconductor?

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