But we haven't yet addressed why, for example, a 2 s orbital islower in energy than the 2 p orbital, or why, for example, a 3 s orbital is lower in energy than a 3 p, which in turn is lower than a 3 d orbital.
但是我们还没有强调为什么,举个例子一个2s轨道能量低于2p轨道,或者为什么,举例来说它依次低于3d轨道,屏蔽一个3s轨道的能量小于3p轨道。
化学原理课程节选 : 麻省理工公开课