So in terms of total numbers that we would need to complete our octets and fill our valence shells, we would need 18 electrons.

因此要填满我们的“八隅体“,排满所有的价壳层，我们总共需要十八个电子。

麻省理工公开课 - 化学原理课程节选

The reason is because we already have a full valence shell for our hydrogen, it doesn't want any more electrons.

原因是因为我们的氢,已经有一个排满的价壳层了，它不再需要多余的电子了。

麻省理工公开课 - 化学原理课程节选

So to figure out bonding electrons, -- what we take is that number 18, which is our total number of electrons we need to fill valence shells, and we subtract it from our number of valence electrons, which is 10.

那么为了找出成键电子，我们将十八，也就是填满所有价壳层,所需要电子的总个数，减去我们所有的价电子的个数，也就是十。

麻省理工公开课 - 化学原理课程节选