So in terms of the first step of skeletal structure, this is actually going to be easier because we don't have a central atom, we just have carbon and nitrogen here.

对于第一步画出骨架，其实比刚才更容易,因为我们没有一个中心原子，我们这里只有碳和氮两个原子。

麻省理工公开课 - 化学原理课程节选

Step three in our Lewis structure rules is to figure out how many electrons we would need in order for every single atom in our molecule to have a full valence shell.

路易斯结构规则的第三步是,找出让分子中每个原子的价壳层,都排满应该需要多少个价电子。

麻省理工公开课 - 化学原理课程节选

What did we know at the end of the 19th century about the structure of the atom?

在19世纪末,关于原子结构我们了解多少呢？

麻省理工公开课 - 固态化学导论课程节选

In terms of picking a Lewis structure that's going to be the lowest energy, what you want to do is put the atom with the lowest ionization energy in the center of your atom.

为了挑选一个具有,最低能量的路易斯结构，你需要把电离能最低的原子,放在最当中的位置。

麻省理工公开课 - 化学原理课程节选

So, which atom would you expect to be in the center of a Lewis structure for thionyl chloride?

那么，大家认为那个原子应该在,亚硫酰氯的路易斯结构的中心位置呢？

麻省理工公开课 - 化学原理课程节选

So for some you that are less interested in maybe the physical structure of an individual atom, now some more exciting material for you might be coming up if you like to think about how, instead, molecules behave, either within bonding, within themselves, or with other molecules, that's what we're going to be heading to in this next unit.

那么对于某些同学，你们或许不感兴趣,对于单个原子的物理结构，现在可能有令你感到兴奋的内容,要出现了，如果你更喜欢思考,分子的行为，或者是关于成键的，或者是关于它们本身的，又或者与其它分子之间的行为，这些将是我们下个单元要讲的内容。

麻省理工公开课 - 化学原理课程节选

It's always a good first approximation, because you need to start somewhere in terms of drawing Lewis structures, but then if you go and figure out the formal charge and you just have lots of charge separation or very high charges, like a plus 2 and a minus 2 and a minus 1 all different places in the atom, what it should tell you is maybe there's a better structure.

它总是一个好的第一近似，因为在画路易斯结构的时候,你总需要一个起点，但是如果你在算出形式电荷之后,发现有很多电荷分开了,或者说有很高的电荷，比如有一个正二，一个负二，还有一个负一1,在原子的各个地方，这应该就是在告诉你,或许还有一个更好的路易斯结构。

麻省理工公开课 - 化学原理课程节选

Often a good thing to start with is to put the lowest ionization energy atom in the middle, and if you don't have charge separation then go with that structure, but if you do find you have a lot of separation, such as the case in negative 2, positive 2, and minus 1, then you want to say wait a second, this is really bad in terms of formal charge, let me go ahead and see what other options I have here.

通常一开始把电离能最低的原子,放在中心位置就很好了，如果你发现电荷没有分开,那么这个结构就没问题了，但是如果你发现有很多分开的电荷，比如这种情况，有负二，正二和负一，那么你会想要说等一下，从形式电荷来看这很不好，让我去看看其它可能的选择。

麻省理工公开课 - 化学原理课程节选