So here we have energy increasing on the y-axis, and you see this straight line at the bottom here is lower down on the graph, and that's the energy of a bound electron, so that's going to be a low stable energy.

这里我们看到能量沿着y轴增加，而且在这张图片上,这条直线在底部是降低的，那是一个束缚电子的能量，所以那是一个低稳态能量。

麻省理工公开课 - 化学原理课程节选