While in New York, Mr.Obama also addressed a high-level summit on climate change,called by U.N.Secretary-General Ban Ki-moon.

VOA: standard.2009.09.22

We'll get to discussing that, but what I want to point out here again is the fact that instead of just being dependent on n, the energy level is dependent on both n and l.

我们将要讨论它，但是我想指出的是事实上能级不只是与n有关,而是与n和l都有关系，而且n不再是。

麻省理工公开课 - 化学原理课程节选

They're not going to want to add on another electron, because then it'll have to jump a very large energy level go from n equals 2, to n equals 3, and n equals 4, and so on.

它们不愿意增加另外一个电子，因为这会让它们跳到一个非常高的能级上去,依次是，n，等于，2，3，4，等等。

麻省理工公开课 - 化学原理课程节选

O Right there, order n. So I have order n operations at each level in the tree. And then how many levels deep am I? Well, that's the divide, right? So how many levels do I have?

在这儿,所以我在树的每个层次都要做O的操作,那个这棵有多少层呢？,这是一个除法，不是吗？

麻省理工公开课 - 计算机科学及编程导论课程节选

So, our next level up that we can go is going to be the n equals 2 energy level, but we also have an l and an m value, 0 so our lowest l is going to be a there.

所以下一个能量,是n等于2的能级，但我们还有l和m的值，所以我们最低的l等于。

麻省理工公开课 - 化学原理课程节选

So if we go to the ground state, what you see is we're at that lowest energy level, and we only have one possibility for an orbital, because when n equals 1, that's all we can do.

如果我们在基态上，你可以看到，我们在能量最低的态上，只有一种，可能的轨道，因为n等于1，只有这种可能。

麻省理工公开课 - 化学原理课程节选

So what we'll do is this problem here, which is let's calculate out what the wavelength of radiation n would be emitted from a hydrogen atom if we start at the n equals 3 level and we go down to the n equals 2 level.

我们来做这个问题,让我们来计算一下,从n等于3到,等于2能级氢原子辐射的波长是多少。

麻省理工公开课 - 化学原理课程节选

So this is our final equation, and this is actually called the Balmer series, which was named after Balmer, and this tells us the frequency of any of the lights where we start with an electron in some higher energy level and we drop down to an n final that's equal to 2.

把2代入到这里，所以得到1除以,这就是我们最终的方程，这叫做Balmer系，以Balmer名字命名的,它告诉我们从高能级掉到n等于2的,最终能级所发出光的频率。

麻省理工公开课 - 化学原理课程节选