Step three in our Lewis structure rules is to figure out how many electrons we would need in order for every single atom in our molecule to have a full valence shell.

路易斯结构规则的第三步是,找出让分子中每个原子的价壳层,都排满应该需要多少个价电子。

麻省理工公开课 - 化学原理课程节选

What's more interesting is below even that there may be unconscious associations that work that people don't actually know about but affects their thoughts about race, gender and other social groups.

更有趣的是第三层,刻板印象还会在潜意识在起作用,人们根本意识不到这点,但它现样会影响人们关于种族，性别和其他社会群体的看法。

耶鲁公开课 - 心理学导论课程节选

So if we write the electron configuration you see that this is the electron configuration here, 1s22s22p 1 s 2, 2 s 2, 2 p 6, 3s1 and now we're going into that third shell 3 s 1.

现在我们来到第三层,你们会看到3s1价电子之间的区别，电子构型是，现在我们来到第三层。

麻省理工公开课 - 化学原理课程节选

s But it just turns out that the 4 s is so low in energy that it actually surpasses the 3 d, because we know the 3 d is going to be pretty high in terms of the three shell, and the 4 s is going to be the lowest interms of the 4 shell, and it turns out that we need to fill up the 4 s 4s before we fill in the 3 d.

但是结果是,能量较低,4s是第四层最低的，因为我们知道3d在第三层,是非常高的，4s是第四层,最低的，结果是我们在填充3d之前,需要先填充。

麻省理工公开课 - 化学原理课程节选