And if we put that in our bond here, we have 1, 2, 3 bonds, plus we have one lone pair left over.

如果我们把它们放到键里，我们有1，2，3个键，还剩下一对孤对在这里。

麻省理工公开课 - 化学原理课程节选

A covalent bond is any time we have a pair of electrons that is shared between two different atoms.

所谓共价键就是我们有两个原子,共用一对电子。

麻省理工公开课 - 化学原理课程节选

We have another pair of stops.

这有另外一对挡板。

麻省理工公开课 - 热力学与动力学课程节选

Because we have paired set in a 2 s orbital, so all we're left essentially is two electrons that are available for bonding.

因为我们有一对，在2s轨道里已经配对了,所以只剩下两个电子可以用来成键。

麻省理工公开课 - 化学原理课程节选