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

So, using our simple valence bond theory, what we would expect is that we want to pair up any unpaired electrons in methane with unpaired electrons from hydrogen and form bonds.

利用简单的价电子成键理论，我们预计,要把所有甲烷中没有配对的电子,和氢原子中没有配对的电子配对来形成键。

麻省理工公开课 - 化学原理课程节选