9 or . 8 7 are possible, they actually aren't possible because even if we saw a total shielding, 1 the minimum z effective we would see is 1.

。39和0。87是可能的，实际上它们是不可能的因为即使,我们看到了一个完全的屏蔽，最小的有效电荷是。

麻省理工公开课 - 化学原理课程节选