• 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,还剩下一对对在这里。

    麻省理工公开课 - 化学原理课程节选

  • You can actually see the mechanics of end-stopped verse quite clearly in the rhymed version of Paradise Lost that, admittedly, the great poet John Dryden wrote.

    在大诗人约翰·德莱顿所写的,押韵版的《失乐园》中能很明显看到,这中联诗句的机制。

    耶鲁公开课 - 弥尔顿课程节选

  • 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

  • Place the non-bonding pairs on peripheral atoms first, which the higher average valence electron energy.

    首先将对电子放在外围的原子,那儿具有较高的平均价电子能。

    麻省理工公开课 - 固态化学导论课程节选

  • It is not something that can simply be pursued in isolation.

    那并非,可以在离的情况下寻获的。

    耶鲁公开课 - 政治哲学导论课程节选

  • Now most rhymed poems in Milton's day were end-stopped lines of verse.

    弥尔顿时期的大部分押韵诗都使用联诗句。

    耶鲁公开课 - 弥尔顿课程节选

  • If these bonds were all completely of equal distance apart, whether is was a lone pair or bonding electrons, 5° the angles would be 109 . 5 degrees.

    如果不管它是对,还是成键,它们等距分开的话,键角是109。

    麻省理工公开课 - 化学原理课程节选

  • But because there's this lone pair here, it's pushing down on the other bonds, 5° so we end up with an angle of less than 109 . 5 degrees.

    但因为这里有对,它会把其它键向下压,所以键角会小于109。

    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对电子。

    麻省理工公开课 - 化学原理课程节选

  • So in oxygen we have a similar situation where, in fact, we are not going to promote any of the electrons because we have two lone pair electrons no matter what we do.

    在氧中,情况很类似,我们不能激发电子,因为无论如何我们都有两个对电子。

    麻省理工公开课 - 化学原理课程节选

  • Well, we're talking about a pretty high number here, so to make counting easier, we'll just say 10 lone pairs, because 20 lone pair electrons is the same thing as 10 lone pairs.

    好吧,我们这里讨论的是一个挺大的数,为了数起来更容易,我们就说有十对对电子,因为二十个跟十对是一个意思。

    麻省理工公开课 - 化学原理课程节选

  • And step seven is how many electrons do we have left over that are going to go into lone pairs? How many?

    而第七步是我们剩下,多少电子成为对电子?多少?

    麻省理工公开课 - 化学原理课程节选

  • So since we have two lone pairs, we're going to be pushing down even further on the bonding electrons, so we're going to smoosh those bonds even closer together.

    因为我们有了两个对,我们会把成键电子,更加向下压,所以我们把这些键更加紧得推到一起。

    麻省理工公开课 - 化学原理课程节选

  • An end-stopped line is one in which the grammatical unit of sense stops precisely at the end of the line. The next line of verse picks up a different thought and the next one after that, and so on.

    联诗句到了句尾语法和句意,都刚好停止,下一句,又表达一个新的意思,下一句又是,依次类推。

    耶鲁公开课 - 弥尔顿课程节选

  • So in terms of nitrogen that starts off with a valence number of 5, again we have 2 lone pair electrons in the nitrogen, and again, we have 6 electrons that are shared.

    对于氮来说,我们应该从五个价电子开始,同样,氮也有两个对电子,共用电子的个数也一样,是六个。

    麻省理工公开课 - 化学原理课程节选

  • So if we take a look at nitrogen here, what you'll notice is we have thre available for bonding, - and we already have our lone pair -- one of our orbitals is already filled up.

    如果我们看一下氮原子,我们注意到我们可以成3个键,我们已经有一个对-,其中的一个轨道已经被填满了。

    麻省理工公开课 - 化学原理课程节选

  • And it turns out that it's actually less than 109 . 5, because those lone pairs are pushing the bonds even further away.

    所以结果是它要小于109。,因为对会把成键推向更远。

    麻省理工公开课 - 化学原理课程节选

  • For the sulfur, we start off with 6 valence electrons, minus 4 lone pair electrons, minus 2, taking in account our bonding electrons, so we end up with a formal charge of 0.

    对于硫,我们从六个价电子开始,减去四个对电子,再减去二,算上我们的成键电子,因此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

  • So, if we want to figure out the formal charge on the carbon, we need to take the number of valence electrons, so that's 4. We need to subtract the lone pair, what number is that? It's 2.

    如果我们想算出碳原子的形式电荷,我们需要将价电子的个数,也就是四,减去对电子的个数,它是多少?是二。

    麻省理工公开课 - 化学原理课程节选

  • PROFESSOR: Good, good, it's going to be less than, and it's going to be less than because now we have two lone pairs.

    教授:很好,它要更小,因为我们现在有两个对。

    麻省理工公开课 - 化学原理课程节选

  • So, lone pair electrons, actually, not lone pairs themselves.

    注意是对电子,而不是电子对。

    麻省理工公开课 - 化学原理课程节选

  • And if we talk about chlorine, and both of the chlorines are the same in this case, we start with a valence number of 7 for chlorine, and then we subtract 6, because it had 6 lone pair electrons around each of the chlorine atoms.

    而如果我们讨论氯的话,在这个例子中两个氯的情况都是一样的,从七个价电子开始,然后减去六,因为每个氯原子周围,都有六个对电子。

    麻省理工公开课 - 化学原理课程节选

  • or 1 lone pair, 2 lone pair electrons.

    或者说一对对电子,两个对电子。

    麻省理工公开课 - 化学原理课程节选

  • And, how many non-bonding?

    对电子有多少呢?

    麻省理工公开课 - 固态化学导论课程节选

  • 0. 26 minus 6, so that tells us 20, and these are all going to be lone pairs.

    二十个,二十六减去六,因此是二十个,它们都会成为对电子。

    麻省理工公开课 - 化学原理课程节选

  • 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,作为对电子加到我们的结构中。

    麻省理工公开课 - 化学原理课程节选

  • That's what we call when we have three bonding atoms and one lone pair.

    这是当我们有3个成键电子,和一个对时这样称它。

    麻省理工公开课 - 化学原理课程节选

  • So it looks a lot less messy if we just draw our Lewis structure like this for h c n, where we have h bonded to c triple bonded to n, and then a lone pair on the nitrogen there.

    这看起来整洁了不少,如果我们把氰化氢的路易斯结构画成这样的话,这样我们就有氢与碳之间的单键和碳与氮之间三键,然后还有一对对电子在氮这里。

    麻省理工公开课 - 化学原理课程节选

  • So what we see is on ammonia here, 107 we know that it's less than a 109 . 5, it's actually 107, so it's less than a 109 . 5, because of that lone pair pushing down in the bonding electrons.

    我们看到在氨分子里,我们知道它比109.5要小,它是,所以比109。5要小,因为对会把成键电子向下推。

    麻省理工公开课 - 化学原理课程节选

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