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So what we can actually directly compare is the dissociation energy or the bond strength of nitrogen versus hydrogen.
因此实际上我们可以直接进行比较,对氮分子与氢分子的离解能,或键的强度。
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Well, if this bond has completely identically equal sharing of electrons, then this bond will be nonpolar.
如果一根键连的两个原子,对键上的电子吸引程度是完全等价的，那么这根键是非极性的。
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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，还剩下一对孤对在这里。
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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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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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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.
但因为这里有孤对，它会把其它键向下压，所以键角会小于109。
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We see three bonding pairs so this is a triple bond, indeed a multiple bond.
我们看到3对成键电子所以这是一个三重键，它确实是多重键。
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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，我们已经有一个孤对-,其中的一个轨道已经被填满了。
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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。,因为孤对会把成键推向更远。
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And then we have a triple bond there because we have 3 pairs of electrons.
然后那里还有一个三键,因为我们有三对电子。
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This means it is not a strict bond one-to-one.
这意味着不是严格1对1的键。
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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。
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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。
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And we can also talk about the bond length, so we might be interested in what the bond length is, what the distance between these two nuclei are.
另外一点就是键长，我们对键的长度也感兴趣，也就是两个原子核之间的距离。
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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.
因为我们有了两个孤对，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。
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If we think about that, that's a sigma bond, right, they're coming together along the nuclear axis.
如果我们考虑它的话，它是sigma键，对吧，它们沿着核轴方向靠近。
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When you are done you have three electron pairs in bonding orbitals.
当你完成的时候,成键轨道上共有三对电子。
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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 the reason we can see that by looking at this graph is that we see that nitrogen when it's bonded is in an even lower well than we saw for hydrogen.
原因可以通过观察这幅图发现,我们看到氮在成键之后将处于更低的势阱中,对氢而言。
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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，然后还有一对孤对电子在氮这里。
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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，因为孤对会把成键电子向下推。
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So that's exactly what our definition of a pi bond is, so we have one sigma bond, and one pi bond.
这是我们对π键的定义，我们有一个sigma键，和一个π键。
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The bond is the electron pairs.
键就是共用电子对。
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N 2 So any chemist should be able to just look at n 2 and know that it's a triple bond, but that's not something that we've learned how did to do yet, so let's go ahead and start a new topic that's going to allow us to have some sort of sense of what the valence electron configuration, which includes whether something's a single or double or a triple bond can be figured out for any given molecule.
任何一个化学家都应该能够仅仅通过看到2,就知道它有一个三键,但是我们还没学习如何做到这点，因此下面我们就开始进入一个新的主题,它将使我们能够有一定的认识,对于价电子的排布情况，包括可以对任何一个给定分子中的键是单键双键,还是三键作出判断。
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These 2 are going to come together like this, and the first bond that we're going to form is going to be a sigma bond, right, so we see that here. If we're looking head on, we see they form a sigma bond.
它们两个会靠近到一起，首先会形成的是,一个sigma键，对吧，我们在这里可以看出来，我们看到它们形成一个sigma键。
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We have two lone pairs, so if we thought about what the bonds were everywhere, 5° it would be 109 . 5, but it's bent because we're only looking at the bonds, we're not counting the Lewis structures in naming our geometry, but they do affect the angles.
我们有两个孤对，所以如果我们考虑它会成怎样的键时，应该成109。,但它是折线型，因为我们只考虑成键，在几何形状里不考虑Lewis结构，但它会影响角度。
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PROFESSOR: Right, it's a sigma bond.
对，这是sigma键。
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