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The only thing they have to pay on that is a regular interest charge to the IMF as a fee for the conversion of the currency,"
VOA: standard.2009.04.20
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He shot alpha particles which have a charge of plus two.
他入射的阿尔法粒子带有两个正电荷。
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So, let's say we have an atomic number of 3, 3 that means we have 3 electrons, so we better hope to get our neutral atom that we have a charge of plus 3in the nucleus.
这也是很合理的，因为Z就是原子序数，假设原子序数是，那就有3个电子，那我们就希望,性原子有个带3个正电荷的原子核。
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And so we have a positive charge in the nucleus which is given by the number of protons.
在原子核上,有很多质子聚集而形成的正电荷。
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Homes just stay where they are, so we have far fewer accidents, so they don't have to charge as high a premium for the insurance.
而住宅则是固定的,所以发生事故的情况也更少,这就导致保险公司对住房保险收取的保费,不会太高
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So we could think about comparing the potassium ion to a sodium ion. They have the same charge of plus one.
我们可以想象比较一下钾离子,与钠离子，它们都同样带有正一价的电荷。
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For the carbon, we start with 4 valence electrons, we have 0 lone pair electrons minus 4, and we end up with a formal charge of 0.
对于碳，我们从四个价电子开始，我们有零个孤对电子，再减去四，最终我们有零个形式电荷。
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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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Let's re-draw this, so it looks a little bit neater, where we have a triple bond in the middle instead, and again, we need our negative 1 charge there.
让我们重写这个，这样看起来更整洁一点，我们有一个三键在中间，同样地，我们这里需要一个负电荷。
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It turns out, and we're going to get the idea of shielding, so it's not going to actually +18 feel that full plus 18, but it'll feel a whole lot more than it will just feel in terms of a hydrogen atom where we only have a nuclear charge of one.
结果是我们会有,屏蔽的想法,所以它不会是完整的，但是它会比原子核电荷量,吸引力要大很多,只有1的氢原子的。
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Make sure you have batteries that are in a good state of charge in your calculator.
确保你的计算器电池,处在一个良好的状态。
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So, we can also get into a case where we have similar values in terms of absolute values of formal charge between two different molecules we're deciding between in their Lewis structures.
我们还可能遇到另外一种情况,那就是在我们需要进行,选择的两种路易斯结构中,形式电荷具有相似的绝对值。
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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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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 we can do this for any final charge we have, if we have a molecule that has a charge of plus 2, then all of the formal charges should add up to plus 2 and so on.
对于任意净电荷的情况,我们都可以这样做，比如假设我们有一个带两个正电荷的分子，那么所有的形式电荷加起来应该等于正二，等等。
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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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And what's important to keep in mind about formal charge is if we have a neutral atom, such as we did in thionyl chloride here, the sum of the individual formal charges on individual atoms within the molecule have to equal 0.
而关于形式电荷记住一点是很重要的,那就是如果我们有一个中性原子，比如亚硫酰氯，那么这个分子中的所有原子的,形式电荷之和应该等于零。
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And what you find out if you do these calculations, is that you have a negative 1 for your formal charge on nitrogen, you have a negative 2 for your formal charge on carbon, and you have a positive 2 for your formal charge on sulfur.
而如果你做了这些计算会发现，氮的形式电荷量为负一，碳的形式电荷量为负二，而硫的形式电荷量为正二。
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We have the minus because we're adding a negative charge from the electron.
有这个负号的原因是,我们得到一个电子后增加了一个单位负电荷。
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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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Often a good thing to start with is to put the lowest ionization energy atom in the middle, and if you don't have charge separation then go with that structure, but if you do find you have a lot of separation, such as the case in negative 2, positive 2, and minus 1, then you want to say wait a second, this is really bad in terms of formal charge, let me go ahead and see what other options I have here.
通常一开始把电离能最低的原子,放在中心位置就很好了，如果你发现电荷没有分开,那么这个结构就没问题了，但是如果你发现有很多分开的电荷，比如这种情况，有负二，正二和负一，那么你会想要说等一下，从形式电荷来看这很不好，让我去看看其它可能的选择。
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So what we see is that structure a is the most stable because we have the least separation of charge in the case of structure a.
因此我们看到结构，A，应该是最稳定的,因为这种情况下,分开的电荷最少。
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