Sure, and you can pick out the really cold ones, they're wearing little jackets.
(Sorry, I couldn't resist).
Actually, I don't think so. It's more likely an effect of passing a current thru a junction, similar in a distant way of passing a current thru anothet type of junction which causes it to emit light. We never think about which electrons are brighter, it's just the effect of the current flow thru the particular junction.
Electrons can have more or less (heat) energy associated with them. Electrons in orbits around a nucleus will jump to a higher orbit shell if they absorb enough energy. If they absorb energy but not enough to jump to a higher orbit shell, they will just emit a gamma ray (or x-ray or photon) to lower their energy to that required for the shell they are in.
Loose electrons, or any other particle, will exhibit a change in energy level by a corresponding change in their kennitic energy (velocity).
Keep in mind that no one really knows what an electron really is. We observe their behavior and make theories, but what they actually consist of is pretty much up for debate. No one has seen one, and never will.
Radar
