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So why don't you go ahead and identify the correct electron configuration for carbon, 6 and I'll tell you that z is equal to 6 here.
所以你们为什么不开始,而且识别碳的正确的在你们做作业方面,电子构型，我会告诉你有效电荷量是。
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So, if we compare the sulfur to the oxygen, the oxygen it turns out is more electronegative and that is what holds the negative charge in this molecule.
因此，如果我们来比一下硫和氧，氧应该有更高的电负性,而在这个分子中它确实有负的电荷。
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This can't make sense because the plum pudding model says you've got uniformly distributed charge.
这是讲不通的,因为布丁模型说的是电荷在里面均匀分布。
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So for example, that might have a formal charge of negative 1, because to some extent it has gained that much electron density that it now has a formal charge that's negative.
比如，可能它的形式电荷为负一，因为在一定程度上它得到了这么多的共用电子密度,那么它现在就有了负的形式电荷。
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So if you have some charge in the nucleus, but you also have repulsion with another electron, the net attractive charge that a given electron going to feel is actually less than that total charge in the nucleus.
所以如果在原子核中，有一些电荷但是你也有来自，另一个电子的排斥力,那么一个给定电子的,吸引电荷感觉到的事实上,小于原子核中的总电荷。
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All right. So formal charge can actually help us out when we're trying to decide between several Lewis structures that look like they might be comparable in terms of which might be the lower energy or the more stable structure.
好的，形式电荷真的可以,帮助我们决定,在几种路易斯结构中,哪个更可能符合能量更低,或者结构更稳定的要求。
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All right. So let's try one more example of drawing Lewis structures before we talk about formal charge.
好，让我们在讲形式电荷之前,再给一个例子画一下路易斯结构。
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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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So, the question then is what is the spatial distribution of charge inside the atom?
因此，接下来的问题是,原子内部的电荷,在空间如何分布？
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The first is this the z effective, or how much charge is actually in the nucleus that's felt, Z or the I guess we would say the z, how much the charge is on the nucleus that holds it close together.
第一个是有效核电量，或者说实际感受到的核电荷量，又或者我想我可以说就是，使它们保持在一起的,原子核的电荷量。
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So, in this case, we see that our formal charge is negative on the nitrogen, in this case it's negative on oxygen.
那么，在这种情况下，我们看到氮的形式电荷是负的，而在这种情况下，氧的是负的。
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We'll get to oxidation number in the second half of this course, but it's not in any way the same idea as formal charge.
我们会在课程的后半部分讲到氧化数，但它和形式电荷完全不是同一个概念。
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If there is no charge on the plate, these droplets will simply fall under gravity.
如果在板子上没有电荷，这些液滴就只会由于重力掉下。
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So in our first structure, we would find for the nitrogen we have a formal charge 5 minus 4 minus 2, because we're starting with 5 valence electrons, so that is a formal charge of minus 1.
那么在我们的第一个结构中，我们发现氮的形式电荷量是五减去四4,再减去二，因为我们开始有五个价电子，因此它的形式电荷量是负一。
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And shielding is a little bit of a misnomer because it's not actually that's the electron's blocking the charge from another electron, it's more like you're canceling out a positive attractive force with a negative repulsive force.
屏蔽有一点点用词不当,因为它事实上不是,电子阻挡了来自另一个电子的电荷,它更像你在用一个负排斥力，抵消一个正吸引力,但是屏蔽是考虑这个问题,的很好的方式。
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So this means we can actually calculate this for any molecule that we've drawn the Lewis structure for, because we actually do need to draw the Lewis structure before we know, for example, how many of each of these we have, or at least go through the rules.
这意味着我们可以将原来画过,路易斯结构的分子的形式电荷计算出来，因为我们其实在画出,路易斯结构之后才能知道，比如，这些量的值是多少，或者至少我们需要经过前面的那些步骤。
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So this is how much charge there is in a mole of electrons.
这就是在一摩尔的电子里,的电荷量。
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He reasoned then that the charge, since he could vary voltage continuously but got a discontinuous variation in velocity, his conclusion was that the charge must be discontinuously attached to the droplet.
他推断出电荷，因为他可以不断地改变电压,但是得出了速度是在不连续变化着，他的结论是电荷,是间断地依附于液滴上的。
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So there's electron density above the bond and below the bond.
所以在键轴上面和下面都有电荷密度。
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We don't actually have much charge separation in this case here.
我们在这种情况下其实没有很多电荷分开。
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So, an electron has a charge of negative e, we've written here and the nucleus has a charge of positive e.
我们写在这，原子核带正e的电荷,我们看到作用力。
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If we look at our last structure here where we have nitrogen the middle, we can also figure out all those formal charges, and in this case we have plus 1 on the nitrogen, we have minus 2 on the carbon, and then we end up with a 0 on the sulfur there.
如果我们来看看最后一个结构,在中间的原子是氮，我们同样可以计算出所有的形式电荷，而在这种情况下，氮为正一，碳为负二，而最后硫为零。
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So if we have total +2 and complete shielding -1 where that can actually negate a full positive charge, because remember our nucleus is plus 2, +1 one of the electrons is minus 1, so if it totally blocks it, all we would have left from the nucleus is an effective charge of plus 1.
抵消一个完全的正电荷,因为记住我们的原子核是,其中一个电子是,所以如果它完全挡住了它，我们从原子核中留下的，全部有效电荷就是，所以，在我们的第一个例子中,我们的第一种极端情况。
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It's always a good first approximation, because you need to start somewhere in terms of drawing Lewis structures, but then if you go and figure out the formal charge and you just have lots of charge separation or very high charges, like a plus 2 and a minus 2 and a minus 1 all different places in the atom, what it should tell you is maybe there's a better structure.
它总是一个好的第一近似，因为在画路易斯结构的时候,你总需要一个起点，但是如果你在算出形式电荷之后,发现有很多电荷分开了,或者说有很高的电荷，比如有一个正二，一个负二，还有一个负一1,在原子的各个地方，这应该就是在告诉你,或许还有一个更好的路易斯结构。
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The electron completely canceled out 1 it's equivalent of charge from the nucleus, such that we only saw in a z effective of 1.
电子完全抵消了来自原子核的等量电荷,这样我们仅仅看到有效的z为，在极端案例b中。
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