And when we talk about l it is a quantum number, so because it's a quantum number, we know that it can only have discreet values, it can't just be any value we want, it's very specific values.

当我们讲，l是一个量子数时，因为它是量子数，我们知道，它只能去分立的值，它不能取到所有的数，它取一些确定的数。

麻省理工公开课 - 化学原理课程节选

Core electrons are all those electrons held in really tight with the nucleus in the inner shells, whereas the valence electrons are only those electrons that are in the outer-most shell, or at your highest value of n of the principal quantum number.

芯电子是那些,在内壳层被原子核束缚得非常紧的电子，而价电子只包括,最外层的电子，或者说主量子数，n，的值最大的那些电子。

麻省理工公开课 - 化学原理课程节选

The other main difference that we're really going to get to today is that in multi-electron atoms, orbital energies depend not just on the shell, which is what we saw before, not just on the value of n, but also on the angular momentum quantum l number. So they also depend on the sub-shell or l.

我们今天要讨论的,另一个很重要的区别就是,在多电子原子中，轨道能力不仅仅依赖于，我们以前看到的外层，不仅仅依赖于n的值，而是与角动量量子数也有关系,所以它们也依赖于亚外层或者。

麻省理工公开课 - 化学原理课程节选