And, likewise, if we look at fluorine in its diatomic molecule, it is 160 kilojoules per mole.

一样的，如果我们观察二价的氟，它是每摩尔160焦。

麻省理工公开课 - 固态化学导论课程节选

So, selenium 2 minus is what's going to be isoelectronic, because if you add two electrons to selenium, you'll get the same electron configuration that you have for krypton here.

负二价的硒离子将是等电子的，因为如果你给硒原子加上两个电子，你会得到,和氪原子相同的电子排布。

麻省理工公开课 - 化学原理课程节选

What about lithium 2+?

那么二价的锂呢？

麻省理工公开课 - 固态化学导论课程节选

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。

麻省理工公开课 - 化学原理课程节选

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。

麻省理工公开课 - 化学原理课程节选

So, we can say that -- if we have neon here and we want to think about what's isoelectronic, -- f minus would be isoelectronic. We also have oxygen -- what would the charge on oxygen be? Um-hmm, right. 2 minus.

那么，我们可以说--如果我们这里有氖原子,而我们想知道与它等电子的是什么，负一价的氟离子就是与它等电子的，我们还有氧-,氧应该是几价的？没错，负二价。

麻省理工公开课 - 化学原理课程节选

So, what we call this is the third ionization energy, or the negative of the binding energy, again of the 2 s orbital, but now it's in boron plus 2 to we're starting with.

那么我们称它为第三电离能，或者负的束缚能，还是，2，s，轨道的，但现在我们是从正二价硼离子开始的。

麻省理工公开课 - 化学原理课程节选

The highest occupied orbital is now the 2 s orbital, 1 s 2 2 s 1 so we're going to end up with boron 2 plus 1 s 2, 2 s 1, plus the electron coming out of there.

现在最高的被占据轨道是，2，s，轨道，因此结果应该是正二价的硼，再加上一个出射的电子。

麻省理工公开课 - 化学原理课程节选

And what I want to point out that we just figured out for molecular orbital theory, is that o 2 is a biradical, because remember, the definition of a radical is when we have an unpaired electron.

我要指出的是,我们刚利用分子轨道理论，指导了O2是二价自由基，因为记住，自由基的定义是,有个未配对的电子。

麻省理工公开课 - 化学原理课程节选