So we started with 10 valence electrons, we used up 8 of those electrons in terms of making bonds.

我们一开始有十个价电子，然后用掉了八个电子来成键。

麻省理工公开课 - 化学原理课程节选

And carbon 14, 6 again and it has 8, and it is found in vanishingly small amounts, 10 10 to the minus 12 or part per trillion.

碳14，6个质子，8个中子，它的存在是非常微小的，几乎趋于零，万亿分之。

麻省理工公开课 - 固态化学导论课程节选

And if we do that calculation, what we find out is that the binding energy, in this case where we have no shielding, 72× is negative 8 . 7 2 times 10 to So, let's compare what we've just seen as our two extremes.

我们会发现结合，能在这个情况中，没有屏蔽，等于-8。,所以我们来对比一下,我们在两个极端的案例中看到了什么。

麻省理工公开课 - 化学原理课程节选

So what I want to point out with this case in beryllium is that you don't have to use all of the electrons to figure out the bond order, and in fact, once you get to molecules 10 that are from atoms with atomic numbers of 8 or 10, you're not going to want to maybe draw out the full molecular orbital diagram.

我要指出的是,在Be这种情况下,你不需要利用,所有的电子来指导键序，实际上，一旦分子中,原子序数到达了8或者，你也许不想画出,整个分子轨道图。

麻省理工公开课 - 化学原理课程节选