So again, what we see is the same pattern where the most probable radius, if we talk about it in terms of the d, that's going to be smaller then for the p, and the 3 p most probable radius is going to be closer to the nucleus than it is for the 3 s most probable radius that we're looking at.

同样的，我们可以看到相同的行为,ｄ轨道的，最可能半径，比ｐ轨道小，3p轨道的,最可能半径,比3s轨道离原子核更近。

麻省理工公开课 - 化学原理课程节选

And what he came out with when he did some calculations is that there's the radius that he could calculate was equal to this number a sub nought, which is what we call the Bohr radius, and it turns out that the Bohr radius happens to be the radius most probable for a hydrogen atom.

等于这个a0的值,我们叫它波尔半径，而,波尔半径恰好是,最容易，找到电子的地方，我们对波尔模型,不做过多的解释,这是因为。

麻省理工公开课 - 化学原理课程节选