I mean, if the energy is lower to occupy a smaller volume, then if I have this room and a bunch of molecules of oxygen, and nitrogen and what have you in the air, and there are weak attractions between them, why don't they all just sort of glum together and find whatever volume they like.

我的意思是，如果占据小的体积会使能量降低，如果我有这样一个空间,和一些氧气，氮气和其他空气中有的气体，并且分子之间还有微弱的相互作用，为什么他们不黏在一起,然后占据他们所想要占据的体积。

麻省理工公开课 - 热力学与动力学课程节选

z And what you need to remember is if the z 8 is equal to eight or greater, such as oxygen being the cut-off point, this sigma 2 p orbital is actually lower in energy than the pi 2 p orbitals, the molecular orbitals.

你们要记住如果,等于或者大于，就像O是分界点，这时sigma2p轨道,比π2p轨道能量更低。

麻省理工公开课 - 化学原理课程节选