And if we talk about chlorine, and both of the chlorines are the same in this case, we start with a valence number of 7 for chlorine, and then we subtract 6, because it had 6 lone pair electrons around each of the chlorine atoms.

而如果我们讨论氯的话，在这个例子中两个氯的情况都是一样的，从七个价电子开始，然后减去六，因为每个氯原子周围,都有六个孤对电子。

麻省理工公开课 - 化学原理课程节选

And then if we think about 3 s, 0 we want to start with 3, we subtract 1, again l is equal to 0, so minus and we have two radial nodes.

我们从3开始，减去，同样的l等于，所以减去0，我们有两个节点，这应该。

麻省理工公开课 - 化学原理课程节选

pxa So what happens when we add a 2 p a and we subtract from it a 2 p x b, or the same with a 2 p y a subtracting a 2 p y b, is that we're actually going to cancel out the wave function in the center, so we now have 2 nodal planes.

当我们用,减去2pxb时，或者是2pya减去2pyb时，我们会消去,中间的波函数，所以现在我们有两个节面。

麻省理工公开课 - 化学原理课程节选