Question

Which, if any, of the following is/are reasons that a material is a good electrical conductor?

Answer 1

There is an energy band gap, but the Fermi energy is well within an unfilled energy band.
Because there are no gaps in the energy bands of the material
The Fermi energy is in the middle of an energy gap that is more than 3 eV wide.
There is a small (~1 eV ) energy gap between the filled valence band and the next higher band where electrons can exist.
There is an energy gap between the valence band and the conduction band, but it is only a few eV wide.
None of the above statements are true.

Answer 2

I thought it was just because there are no gaps in the energy bands, but that was false

Answer 3

Very small band gaps are also okay, just so long as electrons can get up to the conduction band with primarily thermal excitation.

Answer 4

so I guess "There is a small (~1 eV ) energy gap between the filled valence band and the next higher band where electrons can exist" would be the only true statement?

Answer 5

still slightly confused

Answer 6

There are multiple true statements, you appear to have to select the correct ones.