So if you flip the info page over on the back here, what you'll see is the periodic table, this is the same one that I've handed out in the last two lectures - the periodic table without any electron configurations.

将这张纸翻过来，你可以看到一个元素周期表，这与我们前两次课发过的,是一样的,-没有任何电子排布的周期表。

麻省理工公开课 - 化学原理课程节选

So that's just a little bit of a check for yourself, and it should make sense because what you're doing is you're calculating the difference between energy levels, so you just need to flip around which you put first to end up with a positive number here, and that's a little bit of a check that you can do what yourself.

所以你们总要确保括号，离得这项是正的，这是你们自己,可以做的检查，这事很有道理的，因为你们做的是计算能量差,所以你需要调整顺序来保证一个正数，这是你们自己可以做的检查。

麻省理工公开课 - 化学原理课程节选