So what I want to point out is 3d2 what we said now is that the 3 d 2 is actually lower in energy, so if we were to rewrite this in terms of what the actual energy order is, 3d2 4s2 we should instead write it 3 d 2, 4 s 2.

所以我们想指出的是,我们现在所说的是,实际上能量比较低，所以如果我们重新的,写出实际的能量顺序，我们应该写出。

麻省理工公开课 - 化学原理课程节选