"I think in a year's time,you're going to see a much closer U.S.-Saudi relationship than you have now, and I think it's good that the president is stopping off,"

VOA: standard.2009.06.02

That's the huge force that we're talking about in terms of making a bond stable, but there are also repulsive forces, so you can imagine we're going to have electron-electron repulsion between the two electrons if we're bringing them closer together.

正是这个非常强的力,使得我们所讨论的这个键能够稳定存在，但是其中还有排斥力存在，大家可以想象一下,我们会有电子与电子之间的排斥力,如果让它们离得更近。

麻省理工公开课 - 化学原理课程节选

So when we talk about the size of multi-electron orbitals, they're actually going to be smaller because they're being pulled in closer to the nucleus because of that stronger attraction because of the higher charge of the nucleus in a multi-electron atom compared to a hydrogen atom.

所以当我们讨论,多电子轨道的尺寸，它们实际上会变得更小,因为多电子原子的原子核,相比于氢原子,有更高的电荷量所以,有更强的吸引力,所以可以拉的更近。

麻省理工公开课 - 化学原理课程节选