Question

Give reasons for differences in conductivity using the words "particles", "conductor", and "transfer.

Answer 1

What level of physics is this for? Are you looking at band structures?

Answer 2

idk?

Answer 3

Well, the difference between superconductors, conductors, semi conductors, and insulators is in how easily the particles that we call electrons can flow along the material. The easier they are able to flow, the better they can conduct electricity.

Looking at band structures can tell us a bit of why this happens, although I get the feeling this isn't quite what you are looking for. A "band" is a group of electron energy levels that are grouped very closely together in value. There will be a gap, and then another band starts.

If the outer electrons do not fully fill the band they are in (the valence band), then the material will have low resistance, high conductivity, and is considered a conductor.

If the valence band is full, and the gap between that band and the next band is small, the material is a semi conductor. This allows the material to conduct electricity with relative ease, as an electron can "jump" up to the next band (called the conduction band) by absorbing a little energy and move around more freely.

If the valence band is full, and the gap between that band and the next is large, then the material is an insulator. It's difficult for an electron to acquire the energy needed to jump from the valence band to the conduction band, and so the electrons don't flow very easily.

A (poor) drawing to illustrate this:



Note that the "gap" isn't a physical thing, really. It's the amount of energy the electron needs to "live" there.

Superconductors are a bit of a different beast. Superconductors are materials through which electrons flow through without resistance. If you have a ring of a superconducting material, and a current is flowing through it, it would flow forever unless you stopped it.

There are a few theories as to how this works. One theory is that of Cooper Pairs. The electrons pair up to become bosons, and thus are no longer bound by the rules that originally kept them apart from one another, and can flow freely.