And when we talk about size, I'm again just going to say the stipulation we're not talking about an absolute classical concept here, but in general we're going to picture it being much further away from the nucleus as we move up in terms of n.

当我们说到尺寸时，我们只是说――,经典的绝对的概念，而是它大约,离原子核有多远。

麻省理工公开课 - 化学原理课程节选

putting all those things together, if you looked at this question again we'd get 100% on it, 0 9 that our only option here is 0. 9, and that it's not the negative, it's the positive version, because we're talking about how much energy we have to put into the system in order to eject an electron.

把这些放在一起，你们再看一下题目,大家100%都能选对，我们唯一的选择就是这个，它不是负数，它是正的，因为我们说的，是要,把电子激发出来,需要提供的能量。

麻省理工公开课 - 化学原理课程节选