00:01
Okay, so part a asks us what the bang gap energy tells us about the conductivity of a material.
00:05
So the bang gap energy is the energy gap between the conducting and valence layers of a material.
00:28
So, for instance, in a conductor, there's no gap.
00:32
So all electrons are sort of free to move and conduct about the material.
00:37
So that's a conductor.
00:39
In a semiconductor, there is a little gap.
00:42
So this is the valence layer and this is the conducting layer.
00:51
And there's a little gap here and this is the energy gap.
00:53
And this means that in order for a valence electron to access the conducting layer, it needs to be supplied with an energy eg.
01:00
In an insulator, there's a big energy gap between the valence and conducting layers...