So, if we start instead with talking about the energy levels, we can relate these to frequency, because we already said that frequency is related to, or it's equal to the initial energy level here minus the final energy level there over Planck's constant to get us to frequency.

如果我们从讨论能级开始，我们可以联系到频率上,因为我们说过频率和能量相关,或者说等于初始能量,减去末态能量除以普朗克常数。

麻省理工公开课 - 化学原理课程节选