So how many lone pair electrons do we have?

那么我们有多少孤对电子呢？

youdao

So, which atom is in need of those lone pair electrons?

那么，哪个原子需要这对孤对电子呢？

youdao

So we need to add those 2 valence electrons left as lone pair electrons in our structure.

因此我们需要将这两个剩下的价电子,作为孤对电子加到我们的结构中。

youdao

For the carbon, we start with 4 valence electrons, we have 0 lone pair electrons minus 4, and we end up with a formal charge of 0.

对于碳，我们从四个价电子开始，我们有零个孤对电子，再减去四，最终我们有零个形式电荷。

麻省理工公开课 - 化学原理课程节选

Yeah, so also 4. We started with 10 valence electrons, we used up 6 of those as bonding electrons, so we have 4 left, which will be lone pair electrons.

对，也是四个，我们从十个价电子开始，只用了六个来成键，因此我们还剩下四个，它们将成为孤对电子。

麻省理工公开课 - 化学原理课程节选

And we give different names, depending on what kind of electrons we're dealing with, so, for example, with h c l here, we can talk about having bonded versus lone pair electrons.

我们还起了不同的名字，给我们要处理的不同类型的电子，以氯化氢为例，我们来介绍一下成键电子与孤对电子。

麻省理工公开课 - 化学原理课程节选