So, in this case, we're just drawing the molecular orbital diagram for the valence electrons, so we have three for each.

所以在这个例子里面，我们只需要画出,价电子的分子轨道图，所以每个有3个电子。

麻省理工公开课 - 化学原理课程节选

OK PROFESSOR: Valence electrons. OK, sometimes you're going to be asked to draw a molecular orbital diagram where you're asked to include all electrons, and sometimes it will specifically say only include valence electrons.

教授：价电子，有时候你画一幅分子轨道图,有时候要求你画出所有的电子，有时候特别要求,只包括价电子。

麻省理工公开课 - 化学原理课程节选

This should make a lot of sense, because we know that a hydrogen has 1 s as it's outer-most or valence orbital, so it can be filled up just with two 1 s electrons.

这也是很合理的，因为我们,知道氢只有，1，s，轨道,这就是它最外层的轨道或者说价轨道，因此只要两个，1，s，电子就可以将它填满。

麻省理工公开课 - 化学原理课程节选