But we see if we have a free electron, as we do in this dotted line here, that's going to be a higher energy that's less stable.

但是我们看到如果,我们有一个自由电子，就像虚线所示那样，那将会是一个较高的,不够稳定的能量。

麻省理工公开课 - 化学原理课程节选

So, if we want to go from that stable state to that less stable state, we need to put in a certain amount of energy to our system, that difference between the free electron and the electron bound to the metal.

所以，如果我们想使电子,从稳态到达不够稳定的状态，我们需要引入一定数量的,能量到系统中，即自由电子和束缚于金属的,电子的能量差。

麻省理工公开课 - 化学原理课程节选