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So, if we hybridize just these three orbitals, what we're going to end up with is our s p 2 hybrid orbitals.
我们会看到现在有3个未配对的电子，可以成键。
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So we started with 10 valence electrons, we used up 8 of those electrons in terms of making bonds.
我们一开始有十个价电子，然后用掉了八个电子来成键。
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And so this lower level is called a bonding orbital, and it is a bonding molecular orbital.
所以能级较低的轨道叫做成键轨道，这就是成键分子轨道。
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So we can have four total hydrogens bonding here, - and we can think about how to describe these carbon- carbon bonds.
我们这里一共有四个氢原子成键，我们可以考虑怎么来-,描述碳碳键。
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So we can think about now doing bonding, and now we have four equal orbitals with one electronic each.
我们现在可以考虑成键了，现在我们有4个等价的轨道，每个上面有1个电子。
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So what we end up with in terms of our bonding electrons is going to be 6 bonding electrons.
因此最终我们需要六个成键电子,那么我们可以来把它们填上。
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And what you find is when you have a bonding orbital, the energy decreases compared to the atomic orbitals.
你们发现当你有个成键轨道的时候，相比原子轨道能量要降低。
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It turns out that the antibonding orbital is a little bit higher from the atomic orbital level than the bonding orbital is lower.
这证明了,反键轨道,比原子轨道高,成键轨道比原子轨道第。
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So, we'll start today talking about the two kinds of molecular orbitals, we can talk about bonding or anti-bonding orbitals.
今天我们先来,讨论两种分子轨道，我们要讨论成键和反键轨道。
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we know that h is always terminal, right after the molecule that it's attached to.
我们知道氢原子永远都在末端，放到和它成键的分子的后面。
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So what I want to point out is that it creates an effect that is exactly opposite of a bond.
我要指出的是,它造成的效果和成键正好相反。
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He needs to know about the structures of the molecules, because if the structure is wrong it's not going to work.
他想要让它们成键，他需要知道分子结构，因为如果结构不对。
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So let's see, we started with 8 bonding electrons, and we used up only 4, so the answer is yes, we have 4 bonding electrons left.
那么让我们来看看，我们一开始有八个成键电子，然后只用掉了四个，因此答案应该是还有剩余，我们还剩下了四个成键电子。
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All right, so the bonding order, you're correct, should be 2, if we subtract the number of bonding minus anti-bonding electrons and take that in 1/2.
好，你们是对的，键序为，如果我们用成键数,减去反键数除以2。
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So specifically, what we do associate them instead is within molecular orbitals, and what we say is that they can be either in bonding or anti-bonding orbitals.
特别的，我们把它们和,分子轨道相联系起来，我们说它们可以成为,成键轨道或者反键轨道。
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so you can see that there is going to be two sets in antibonding, three sets in bonding for a net of one, giving us the single bond.
因此你能看到,反键轨道上有两组，三组成键，得到一组净成键，所以成的是单键。
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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.
如果不管它是孤对，还是成键，它们等距分开的话，键角是109。
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However, on Friday we will use a different approach so we can talkabout bonding within atoms that have more than two atoms, molecules with more than two atoms.
但是，在周五我们,会用一种新的办法来讨论,不止两个原子的分子的成键。
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And the other thing to point out is that the energy that an anti-bonding orbital is raised by, is the same amount as a bonding orbital is lowered by.
另外一个要指出的事情是,反键轨道引起的能量升高，和成键轨道引起的能量降低是相同的。
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You might have thought before we started talking about molecular orbital theory that non-bonding was the opposite of bonding, it's not, anti-bonding is the opposite of bonding, and anti-bonding is not non-bonding.
你也许在我们讨论分子轨道之前,就想过非成键时成键的反面，它不是，反键才是成键的反面，反键不是非成键。
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So, for starters we'll keep that as our zero energy, we're going to change it soon to make something that makes more sense in terms of bonding, but we'll keep that as zero for now.
因此，首先我们将会保持零点能的这个定义，但很快我们就会对它进行修改,使它在讨论成键时更合理，但是目前我们还是暂时采用这种定义。
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And when we talk about covalent bonds, there's 2 properties that we'll mostly focus on, and that's going to be thinking about the bond strength or the energy by which it stabilized when it bonds.
而当我们讨论共价键的时候，有两点特性是我们最关注的，那就是键的强度,或者说成键之后能量降低了多少。
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And it turns out that when you constructively have two p orbitals interfere, and when I say constructively, I mean they're both either positive or they're both the negative lobes, that's when you got bonding.
当两个ｐ轨道,相长干涉时，我说的相干相长，意思就是说它们要么都是,正的叶瓣要么都是负的叶瓣，这时就能成键。
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We could also, I think, well, maybe this isn't written out in terms of that convention, which sometimes it's not, so let's also try writing it, such that we have the hydrogen and the oxygen atom there.
我们也可以，我想，好吧，还有可能它不是按照惯例写的，有时候会出现这样的情况，因此，让我们把氢原子和,氧原子成键的情况也写出来。
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And the reason we didn't do that is because we're actually going to spend much of the rest of the course relating these different properties to the properties of molecules in terms of bonding, and also in terms of chemical reactions.
我们至今没有这样做的原因是,实际上我们这门课程以后的大部分时间都将花在,如何将这些性质与分子的性质联系起来,在成键以及化学反应的方面。
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I'm an organic chemist, so I love carbon, it's one of my favorite atoms to talk about, but it would be nice to get to the point of bonding and even reactions to talk about all the exciting things we can think about once we're at that point.
我是个有机化学家，我喜欢碳原子，这是我最喜欢谈论的原子之一，但我更喜欢讲成键,甚至化学反应的概念,一旦到了这之后,我们就可以考虑各种激动人心的事情。
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Now, from your book as well, this is the pz's of the two atomic orbitals forming the bonding orbital.
现在，也是你们书上，这是两个pz轨道,组成的成键轨道。
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So any time you have two atoms bonding, the bond axis is just the axis that they're bonding along.
任何时候如果你有两个原子成键，键轴就是它们成键的方向。
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And this will become more and more clear as we actually talk about these reactions and talk about bonding.
而这将会变得越来越清楚,在我们讨论这些反应以及讨论成键的过程中。
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So it's trigonal because we have these three atoms that are bound to the central atom here, and if you picture it, it's actually shaped like a pyramid.
这里三角形是因为,我们有3个原子核中心原子成键，如果你画它，它就是金字塔形的。
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