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So, what will start with on Monday is doing the most simple example of methane using these Lewis structure rules.
因此，下周一上课,我们会先以最简单的例子--甲烷开始,使用这些路易斯结构的规则。
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It's 109 . 5 is what we would expect for methane because it's tetravalent, but here we're just seeing something that's divalent, and they're both in p orbitals that are perpendicular to each other.
因为甲烷是四价的，我们预测是109。,但这里我们，看到的是二价的，它们都在。
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A good example of that is CH4, because the CH bond is polar but symmetrically disposed in space.
甲烷就是一个很好的例子，因为极性键是,空间对称的。
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Burn coal to make it, catalytic decomposition of methane, you get the hydrogen, where does the carbon go?
通过烧煤得到，催化分解甲烷，可以得到氢，碳去哪儿了？
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As we see a little bit later, I could talk about the carbon-hydrogen bond in methane where there is a plurality of bonds. In this case, there is only the one bond but I just want to get the formulas.
因为我们后来看到一点点，我能讨论甲烷中的碳氢共价键,那有许多共价键，这种情况下，这只有一条共价键,但我想得到氟。
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So this should immediately look like a problem because we know, in fact, that methane is tetravalent, and this is telling us it's only divalent.
显然这看起来是一个问题,因为我们知道实际上，甲烷是四价的，而这告诉我们它仅仅是二价的。
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Here is the question. Is methane a polar molecule or a nonpolar molecule? Let's look carefully.
问题是，甲烷是一个极性分子还是非极性分子,我们仔细看看。
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So, using our simple valence bond theory, what we would expect is that we want to pair up any unpaired electrons in methane with unpaired electrons from hydrogen and form bonds.
利用简单的价电子成键理论，我们预计,要把所有甲烷中没有配对的电子,和氢原子中没有配对的电子配对来形成键。
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We only have the one bond so the actual HF molecule is polar, it has a net dipole.
但HF中只有一根键,所以分子也是极性的而甲烷中有一个网状偶极。
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All right, so let's consider our methane situation now that we have our hybrid orbitals.
好，让我们考虑甲烷的情形,既然我们有了杂化轨道。
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We were talking about methane, which has only one central atom.
我们讨论的甲烷，只有一个中心原子。
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Let's try something like four, which is what? Methane.
试试配位原子有4个的，那是什么东西，甲烷。
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Let's go back to methane and see what happens there.
让我们回到甲烷，看看发生了什么。
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All right, so those are the things that we know about it.
好的，这些是我们对甲烷的了解。
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So let's think about methane using valence bond theory.
让我们用价电子成键理论来看一看甲烷。
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Methane we can draw. It looks like this.
我们可以画出甲烷，就是这样子。
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Let's look at methane.
让我们看看甲烷。
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Well, we know it's stable.
我们都知道甲烷很稳定。
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And so, methane is nonpolar.
甲烷没有极性。
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He did some hybridization of methane.
就是甲烷的杂化。
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What do we know about methane?
关于甲烷我们知道什么？
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Here is methane.
这是甲烷。
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Let's go back to methane.
让我们回到甲烷。
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Methane looks like this with the sp3 hybridization.
甲烷看起来就是sp3杂化的。
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And I picked looking at methane so we could see if there are other factors that we're not considering, that we need to maybe tweak our model a little bit, and I think we'll find that we do if we take a look at a polyatomic molecule, methane, CH4 so c h 4.
我选择甲烷这个例子，我们可以看到,如果有一些我们没有考虑到的因素，我们需要修改一下我们的模型，我们看一看,甲烷CH4这个多原子分子，就会知道这一点，甲烷。
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