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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 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 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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And let's say our second electron now is really far away, such that it's actually not going to shield any of the nuclear charge at all from that first electron.
距离原子核非常非常近,我们说第二个电子处于非常远的位置,这样它不会对第一个电子,感受到的来自原子核的电荷量有任何屏蔽作用,我们最后要说的是。
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So let's do this considering, for example, what it would look like if we were to write out the electron configuration for oxygen where z is going to be equal to 8.
我们来做这个考虑，举例来说,如果我们写出,有效电荷量为8的氧的电子构型。
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But what you should be able to do is take a look at a list of answers for what we're saying z effective might be, and determining which ones are possible versus which ones are not possible.
但是你们应该能够做到的,是看一下这个可能的,有效电荷量的答案列表，并且确定哪些是可能的,哪些是不可能的。
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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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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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So the most basic answer that doesn't explain why is just to say well, the s orbital is lower in energy than the p orbital, but we now have a more complete answer, so we can actually describe why that is.
所以最基本的答案是那没有解释,所以我们事实上可以描述，为什么是那样，但是我们现在有一个更复杂的答案，又是有效电荷量。
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So that means if we add up all of the formal charges within the molecule, what we would expect to see is that they sum up to give a net charge of negative 1.
那么这就意味着如果我们把这个分子中,所有的形式电荷加起来，我们应该会看到它们加起来,之后得到的净电荷量为负一。
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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 our minimum that we're going to see is that the smallest we can have for a z effective 1 is going to be equal to 1.
所以我们能够看到的,最小的有效电荷量,等于。
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So we should be able to calculate a z effective for any atom that we want to talk about, as long as we know what that ionization energy is.
我们应该可以计算出任何一个,我们想要谈论的原子的有效电荷量，只要我们知道电离能是多少。
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So, how could he know that the charge on the two particles was equal?
就是这两种粒子,电荷量是相等的？
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So we end up with a formal charge on carbon of negative 1.
因此最终我们得到碳的形式电荷量是负一。
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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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So what is the charge on a helium nucleus?
那么氦原子核的电荷量是多少呢？
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What is the charge of the nucleus?
原子核的电荷量是多少？
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And the point that I also want to make is the way that they differ, z effective actually differs from the total charge in the nucleus due to an idea called shielding.
我也想指出的一点是它们不同的方式,有效的z事实上不同于原子核的，总电荷量,因为屏蔽效应。
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And what we're actually talking about again is the zeffective. So that z effective felt by the 2 p is going to be less than the z effective felt by the 2 s.
我们实际上所谈论的,所以被2p感觉到的,的有效电荷量,有效电荷量小于2s感觉到。
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We know that it has to be equal to less than 2, because even if we had absolutely no shielding at 2 all, the highest z effective we could have is 2, so it makes perfect sense that we have a z effective that falls somewhere in the middle of those two.
我们知道它必须小于，因为即使完全没有一点屏蔽,最高的有效的z是，所以我们得到的有效电荷量处于,两者之间就非常讲得通了,让我们来看看另一个例子。
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So we know that we can relate to z effective to the actual energy level of each of those orbitals, and we can do that using this equation here where it's negative z effective squared r h over n squared, we're going to see that again and again.
我们知道我们可以将有效电荷量与,每个轨道的实际能级联系起来，我们可以使用方程去解它,乘以RH除以n的平方,它等于负的有效电荷量的平方,我们将会一次又一次的看到它。
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And, q1 is equal to the charge on sodium.
而q1等于钠离子所带电荷量。
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But what's important is not where that most probable radius is when we're talking about the z effective it feels, what's more important is how close the electron actually can get the nucleus.
但重要的不是,最可能半径,当我们谈论它感到的有效电荷量的时候，更重要的是,电子实际上。
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Of course, if we saw no shielding at all what we would end up with 3 is a z effective of 3.
当然如果我们说没有任何屏蔽,我们最后得到的,有效电荷量是。
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And then we end up having 6 shared electrons, 2 from each of the bonds, so we end up with a formal charge on sulfur of plus 1.
然后我们有六个共用电子，每个键两个，因此最终硫的形式电荷量为正一。
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So again, when we check these, what we want to see is that our z effective falls in between the two extreme cases that we could envision for shielding.
所以当我们再一次检查这些时，我们想看到的是,有效电荷量处于两种极端案例中,这两种极端案例。
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Again we have the charge of the nucleus on plus 2, +2 but let's say this time the electron now is going to be very, very close to the nucleus.
对于我们的氦原子，我们有一次得到了原子核电荷量为,但是我们说这次电子。
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They're less shielded because they're closer to the nucleus, they feel a greater z effective.
它们受到少的屏蔽,因为它们离原子核更近，它们感觉到一个更大的有效电荷量。
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