system
Given the following post, respond as if you're commenting on Reddit:
human
Why do some materials conduct electricity while others do not?

I've heard that it is related to the energy levels of electrons or the lattice of the material among other things, but I do not have a good answer as to why some materials conduct electricity while others do not. It is quite difficult to find information relating to electricity on the atomic level.
gpt
When you have a bulk material like rubber (insulator), silicon (semiconductor), and copper (conductor) the electrons energy levels of the individual atoms form energy bands when considering the bulk properties of the material. To move electrons through a material you must promote them from the valence band to the conduction band, in an insulator the band gap is large it takes a lot of energy to promote an electron, with a semiconductor the band gap is small taking only a little bit of energy to promote an electron, and in a conductor the valence band and conduction band are touching so only a very small amount of energy is required to promote an electron.