This week,we talk about smoking C the leading cause of cancer worldwide.

VOA: special.2010.03.09

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

So, in terms of the c l atom, we need to talk about each atom individually.

对于氯原子，我们需要分开讨论这两个原子。

麻省理工公开课 - 化学原理课程节选

He does tell you all about the legends first, but he puts them aside and says they're just legends--now let's talk history, and he doesn't begin that until the eight century B.C.

他先将神话传说展示给读者,然后将其放到一边,对读者说,这些只是神话而已,现在咱们说说历史,而他讲的历史是从公元前八世纪开始的

耶鲁公开课 - 古希腊历史简介课程节选

And the last example that we're going to talk about is thionyl chloride, so it's s o c l 2. This is another good step forward, because now we actually have four different atoms in our molecule.

我们要讨论的最后一个例子,是氯化亚砜，就是硫，氧，氯，二，这又是一个进步，因为我们的分子中现在有四个不同的原子了。

麻省理工公开课 - 化学原理课程节选

So carbon has four valence electrons, so if we talk about c 2, again we're going to start filling in our molecular orbitals, and now we're going to have eight electrons to fill into our molecular orbitals.

碳有4个价电子，所以如果我们考虑C2的话，同样，我们开始填分子轨道，现在我们有8个电子,要填入分子轨道。

麻省理工公开课 - 化学原理课程节选

So let's talk about what the bonding order is going to be for c 2.

让我们讨论一下C2的键序是多少。

麻省理工公开课 - 化学原理课程节选