So between b e, and b, between n and o, magnesium and aluminum, and then phosphorous and sulfur, what we see here is that we're kind of going down, or quite specifically, we are going down.

比如从铍到硼，从氮到氧，从镁到铝，从磷到硫，我们在这些地方看到有点下降，或者可以明确地说，我们确实在下降。

麻省理工公开课 - 化学原理课程节选

So, we have beryllium in the first case here, it has four electrons, that's how we know it's beryllium, boron has five electrons.

那么我们将铍作为第一个例子，它有四个电子，这也是我们为什么能知道它是铍的原因，硼有五个电子。

麻省理工公开课 - 化学原理课程节选

Look at beryllium 2 plus, very tiny, charge plus two.

例如铍二正离子，非常小，带2个单位正电。

麻省理工公开课 - 固态化学导论课程节选

So, let's write this one electron orbital approximation for berylium, that sounds like a pretty complicated question, but hopefully we know that it's not at all, 1s22s2 it's just 1 s 2, and then 2 s 2.

所以让我们写出,铍的单电子轨道近似，那听起来像是一个更为复杂的问题，但是希望我们知道它一点都不是，它仅仅是。

麻省理工公开课 - 化学原理课程节选

And the glitch that doesn't make sense just through periodic trends, is that it turns out that the ionization energy of boron is actually less than the ionization energy up beryllium.

仅仅考虑周期性规律,是无法理解这个问题的，这里显示硼的电离能,实际上比铍的要小。

麻省理工公开课 - 化学原理课程节选