We cannot do anything about protons, they are buried in the nucleus, but we can add or subtract electrons.

我们不能改变质子，它们埋藏在原子核内，但是我们能够增加或减少电子。

麻省理工公开课 - 固态化学导论课程节选

And just to give you a sense, if you do a cross-cut of this, you cannot show it from this angle, but it should really be sort of a dumbbell shape with the nodal plane in between the two nuclei.

告诉你们这些就是给你们点概念，假如你们把他横切切开，不能从角度上展示，但它还是会保留几分哑铃的形态,以及在两核之间的节面。

麻省理工公开课 - 固态化学导论课程节选