Question

Explain band theory.

Answer 1

In solid-state physics, the electronic band structure of a solid describes the range of energies that an electron within the solid may have and ranges of energy that it may not have. 

Answer 2

Band theory is the one that has the theoretical model that is well-described as the electrons state.

The solid material has the energy value that has the specific range and behaviour that can attract the other particles.

They have the forbidden bands that stored up the energies between two electrons.