The examples we've done so far have been pretty straightforward, so we haven't needed to use formal charge to make this kind of decision.

我们之前做过的例题,都是非常简单直接的，因此我们还不需要,用形式电荷来做这种决定。

麻省理工公开课 - 化学原理课程节选

I'm going to give the last class a problem which is pretty interesting, which is what happens to you when you have an elevator.

我将讲解最后一个例题,非常有趣,也就是当你在电梯里的情形

耶鲁公开课 - 基础物理课程节选

So let's do a sample calculation now using this Rydberg formula, and we'll switch back to emission, and the reason that we'll do that is because it would be nice to actually approve what we just saw here and calculate the frequency of one of our lines in the wavelength of one of the lines we saw.

让我们用Rydberg公式,做一个例题，我们回到发射上,这么做是因为这样,可以用我们看到的波长,来验证我们计算的频率。

麻省理工公开课 - 化学原理课程节选