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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 everyone is intellectual generally, not everyone, but mostly intellectuals, progressive, high tech.
基本人人都是知识分子，不是每一个，但大部分都是知识分子，进步论者和高技术人群。
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So if we add them all up, there should be no net charge on the molecule, if the molecule is neutral.
因此如果我们把它们都加起来，这个分子上应该没有净电荷，如果这个分子是中性的话。
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It tells you what kind of molecule it is andgives you twovariables that are state variables You could have the volume and the temperature.
告诉你它是哪种分子,还给你了两个状态变量,它们可以是体积或温度。
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Steroids are small molecules - much smaller than proteins - smaller molecules that tend to be hydrophobic or lipid soluble.
类固醇是小分子物质,比蛋白质小得多,这类小分子是非水溶性的,或者说是脂溶性的
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He has this whole group of people out somewhere on the American frontier and they're a kind of a cult.
他描写了来自于美国边界某处的一群人,他们是一群狂热分子
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Here is the atomic nitrogen, here is the atomic nitrogen and these are the orbitals of molecular nitrogen.
这是氮原子，这是氮原子,然后这是氮气的分子轨道。
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Sometimes they were subversive enemies of the Roman order.
有时候是罗马命令的破坏分子。
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This is the fact that we occupy a finite volume in space, because they're little hard spheres in this molecule.
这是由气体分子在空间中,占据有限体积造成的,因为事实上它们是硬的小圆球。
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So that means that the more stable molecule is going to be this molecule here, which actually puts the negative charge on be more electronegative atom.
因此这意味着更稳定的分子,应该是这一个，它真正把负的电荷放到了,电负性更高的原子上。
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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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Many of them are derived from cholesterol and they're hydrophobic, which means they can penetrate through cell membranes.
多数分子都来自于胆固醇,它们是疏水性的,这意味着它们能够穿过细胞膜
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The molecule is net neutral, but this right end is a little bit more negative and the left end is a little bit more positive.
这分子是电中性的，但右边要带一点负电荷,而左边要带一点正电荷。
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So, if we think about the second case here where we have c n minus, now we're talking about a molecule with a net charge of negative 1.
那么，如果我们考虑的是第二个例子,也就是氰离子，那么现在我们讨论的是一个净电荷量为负一的分子。
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So, we'll start by taking a look at constructive interference, and another way to explain this is just to say again, molecular orbitals are a linear combination of atomic orbitals.
我们先来看一看相长干涉，另外一个解释它的方法就是说，分子轨道是原子轨道的组合。
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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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So, for example, down here I wrote that it was n 2 and that it was h 2, but when I re-wrote the molecules up here, you saw that it's an h h single bond where it's a nitrogen-nitrogen triple bond.
比如，在这下面我写的是氮分子2,而这个是氢分子，但我在上面把这些分子的形式改写了，大家可以看到,这是一个氢与氢之间的单键，含一个氮与氮之间的三键。
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So when we talk about formal charge, basically formal charge is the measure of the extent to which an individual atom within your molecule has either gained or lost an electron.
说到形式电荷，基本上形式电荷就是,单个原子在形成分子之后,是得到了电子还是失去了电子的一种量度。
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All right. So, today we're going to be talking about molecular orbital theory, but first I wanted to just mention, in case some of you didn't hear what the Nobel Prize was this morning, and this was in chemistry, it went to three different chemists.
好的，今天我们要讲的是,分子轨道理论，但首先我要说，以免有些同学没有听到,今天早上的诺贝尔奖，这是化学奖，它颁给了3个不同的化学家。
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The other tip I'm going to give you is any time you see a chain molecule, by chain I just mean many different atoms written out in a row.
我要告诉大家的另外一个小窍门是,每当你看到一个链状分子，链状的意思是说很多,不同的原子写成一行的形式。
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Antibiotics are chemicals, usually small organic molecules that will kill micro-organisms like bacteria.
抗生素是一类化学物质,它们通常是小分子有机物,能够杀死细菌这样的微生物
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This is homonuclear and so these are nonpolar.
这是同核分子所以是非极性的。
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Something I'll also point out as you see these dashed line that tell you where the individual molecular orbitals are arising from, as you get to higher and higher atomic numbers of molecules that you're making, it makes a lot more sense to look at a diagram when you draw these dotted lines in, because they can start to get a little bit confusing.
我要指出的是，你们看这些虚线,它们告诉你,每个分子轨道的起源是什么，当你的原子数,越来越高的时候，画出这些点线,使图更容易理解，因为现在开始变得有一点混乱了。
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On the side over here shows a cell membrane and so this is outside the cell above it, and this is inside the cell below, and this is the lipid bilayer that separates the outside of the cell from the inside of the cell.
这边这个表示细胞膜,它的上面代表细胞外部,下面代表细胞内部,这个是脂质双分子层,将细胞内外分开
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Now this behaves very differently in water because part of it is water soluble, this part is, it's a molecule that would like to dissolve in water and part of it is like oil, it doesn't want to dissolve in water.
它们在水中表现出十分不同性质,因为一部分是水溶性的,这一部分是,是一种可以溶于水的分子,而另一部分就像油,不会溶于水中
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We talked about the structure of DNA, how it works in terms of a physical chemical model of the DNA molecules.
上节课我们讲了DNA的结构,从理化模型的角度讲了,DNA分子是如何工作的
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All right, so one thing that I first want to point outabout MO theory that is a big difference from Lewis structures, is that in MO theory valence electrons are de-localized over the entire molecule.
好了，对于MO理论低一点要指出的,是它和Lewis有着很大的区别，在MO理论里,价电子在整个分子里是去局域化的。
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This is sigma star with the antibonding orbital that came from 1s, and it is a molecular orbital.
这是sigma星，来自于1s的反键轨道,它是一个分子轨道。
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So far we've exclusively been using Lewis structures any time we've tried to describe bonding within molecules.
目前为止任何时候我们尝试要,描述分子内的成键,我们都是利用Lewis结构。
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These molecules of DNA, very long molecules of DNA, are condensed and packaged within the nucleus of every cell in your body.
这些DNA分子是非常长的,它们通过折叠等方式压缩形成染色体后,被装配在你身体内的每一个细胞内
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