Question

Draw separate energy band diagrams for conductors, semi-conductors and insulators and label each of them.

Answer 1

Energy band diagrams for conductor, semiconductor and insulator are shown above.
In conductors, both the valance band and conduction band overlap each other. So there is zero band gap in a conductor.
In semiconductor, there is a small band gap approximately of $1eV$.
In an insulator, there is a large band gap of nearly $5eV$.