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In contrast, the dissociation energy of a bond for hydrogen, and molecular hydrogen is everywhere around us, we see 432 kilojoules per mole.
相反，氢分子在我们周围到处都是，一个氢分子的离解能，是432千焦每摩尔。
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So for b 2, which is a single bond, that's 289 kilojoules per mole to break it, and it takes us more energy to break this double bond for carbon, which is 599 kilojoules per mole.
对于B2，它是单键，需要289千焦每摩尔来打破它，而对于碳双键,打破它要更多的能量，等于599千焦每摩尔。
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He said that the percent ionic character, and this is within a bond, not for a compound, for a covalent bond.
他提到离子百分数，是指一根键中，并非一个分子中。
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If it was a twenty-year bond, there would be forty coupons, one for each six-month period, and each one would have a date on it.
假如是20年债券,会有40张息票,每六个月一张,并且上面会有日期
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So let's figure out the bond order for our two molecules here that we figured out the electron configuration for.
让我们看看这里,两个分子的键序是多少。
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And you can go ahead and tell me what you think the bond order is going to be for this molecule.
你们告诉我你觉得,这个分子的键序应该是怎样的。
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And we find the same thing for these two atoms here, it's not actually a double bond, it's somewhere between a single bond and a double bond.
而且我们发现这两个原子的情况是一样的，它其实不是一个双键，而是介于单键与双键之间的。
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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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For hydrogen our bond order is going to equal 1/2, 2 minus 0.
对于氢原子键序等于1/2，2减去。
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It's also important, once we start talking about molecules, to have a way to represent them, and also to be able to look at a shorthand notation for a certain molecule and understand what the bond is.
还有很重要一点是，一旦我们开始讨论分子，我们需要有一种表示它们的方法，而且能够从中看出,某些分子的简化符号，并得知键的类型。
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Clearly, we put 2 for each bond, and now we end up having 2 remaining bonding electrons left.
显然，我们在每个键处放上两个电子，那么最后我们还剩下两个成键电子。
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This is the homonuclear bond energy for hydrogen in pure hydrogen. There we have perfect covalency.
这是氢的同原子的共价能,在纯氢中，我们有完美的共价键。
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OK, he also, let me see, he also, lastly, to close us out, he also developed an analytical expression for the energy of that covalent bond, which is really what we want.
好的，他也，让我看看，他也，最终接近我们的，他也发明了一种分析方式,对于共价键能量来说，这是我们真正想要的。
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Well, there's a formula that's been used by bond traders for hundreds of years and it's a traditional expression, which goes from the discount rate to the price.
这里有个债券交易商,用了上百年的公式,这是个传统表达式,它能用折扣率算得价格
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And something that we'll see later on is that triple bonds, for example, are going to be stronger than a corresponding double bond or a corresponding single bond.
而我们以后还会看到三键，举例来说，应该更强，相较于相应的双键,或者相应的单键来说。
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If we know that this is it the dissociation energy for a hydrogen atom, we can also say the bond strength for hydrogen molecule 424 is 424.
如果我们知道了这是一个氢分子的离解能,那么我们也可以说氢分子的键的强度,就是。
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And the bond order you get out will either be, for example, zero, which would mean that you have no bond, 5 or you could have 1, a single bond, 1 . 5, a 1 and 1/2 bond, 2, a double bond, and so on.
你得到的键序要么是比如说是零，这意味着没有键，或者你会得到1，单键1。,1又二分之一键，2，一个双键，等等等等。
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So, what this lets us do now is directly compare, for example, the strength of a bond in terms of a hydrogen atom and hydrogen molecule, compared to any kind of molecule that we want to graph on top of it.
因此，这让我们现在可以做到直接进行比较，比如，将一个氢原子，和一个氢分子的键的强度，与任何其它类型的分子进行比较,我们只需要把它的曲线也画在这幅图上。
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If we think about bringing in those last two carbons, what you can see is that for every carbon, two of its hybrid orbitals are being used to bond to other carbons.
如果我们考虑引入最后两个碳原子，你会看到的是对于每个碳原子，其中的两个杂化轨道,和另外的碳原子成键。
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What would the bond order be for this bond?
这个键的键序是多少？
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What you could do hundreds of years ago-- and can still do it today-- was go to a bank and present this bond or IOU and say, "What will you give me for it?"
在数百年前你们能做的,在今天还是能够做到的就是,到银行出示这份合约或欠条,问,你们根据它能给我多少钱
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Essentially it would only allow for us to bond to two hydrogen atoms.
本质上，它只能允许我们,和两个氢原子成键。
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So for the bond order we want to take 1/2 of the total number of bonding electrons, so that's going to be 4 minus anti-bonding is 4, so we end up getting a bond order that's equal to 0.
键序等于1/2乘以,总的成键电子数，也就是4，减去反键电子数，也就是4。,所以最后得到键序为0。
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So, if we look at this graph where what we're charting is the internuclear distance, so the distance between these two hydrogen atoms, as a function of energy, -- what we are going to see is a curve that looks like this -- this is the general curve that you'll see for any covalent bond, and we'll explain where that comes from in a minute.
因此，如果我们来看一看这幅曲线图,这里我们画的横坐标是核间距，也就是这两个氢原子之间的距离，纵坐标是能量，我们看到的这是能量关于核间距的曲线-,这是一条普遍的曲线，在研究任何共价键时你都会遇到，我们马上就会解释一下它是怎么来的。
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I'm not going to put Yale's entire portfolio in Google stock, I'm not going to go back and take Yale's entire portfolio to day-trade bond futures; in part, because it would be bad for me personally.
我不会用耶鲁的全部资产买谷歌股票,我也不会,用耶鲁的全部资产买债券期货,一方面是因为,这对我个人不利
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You want to spend your time and energy pursuing the most inefficiently priced asset classes because there's an enormous reward for identifying the top quartile venture capitalist and almost no reward for being in the top quartile of the high- quality bond universe.
你应该投入所有的时间和精力,去追逐最不能有效定价的资产,因为在那里才能通过一流的风投经理人,获得巨额的投资回报,而在债券市场,即使债券优质,经理人一流,回报微乎甚微
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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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When we're talking about r for internuclear distance, we're talking about the distance between two different nuclei in a bond, in a covalent bond.
当我们说，r，代表的是核间距的时候，我们讨论的是一个距离,在一个键--一个共价键的两端的原子核之间的距离。
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