But it doesn't actually cost as much energy as you might think, because in this s orbital here we have a paired electron situation where we're moving up to a p orbital where the electron is no longer paired, so it won't feel quite as much electron repulsion, but nonetheless, this is going to cost us energy.

但它消耗的并没有,你们想象的那么多,因为s轨道里我们电子是配对的,当我们把，电子移到p轨道,电子不再配对，所以它不会感受到那么多的电子排斥，但尽管如此，这个过程还是要消耗能量的。

化学原理课程节选 : 麻省理工公开课