That makes sense because we're losing energy, we're going to a level lower level, so we can give off that extra in the form of light. And we can actually write the equation for what we would expect the energy for the light to be.

这很合理，因为我们在损失能量,我们要到一个更低的能级去,我们要以光的形式给出额外的能量,我们可以写下光能量的方程。

麻省理工公开课 - 化学原理课程节选

So, if you use a black lamp or something and you excite something up to a higher energy level and then it relaxes back down to its lower energy state, it's going to emit a new wavelength of light, which is going to be visible to you.

如果你用一个紫外灯或别的,东西把某种分子激发到,更高的能级，然后它会掉回,到低能级，它就会释放,一个新的波长的光,这个光是可见的。

麻省理工公开课 - 化学原理课程节选

Absorption is just the opposite of emission, so instead of starting at a high energy level and dropping down, when we absorb light we start low and we absorb energy to bring ourselves up to an n final that's higher.

吸收就是发射的逆过程,与从一个高能量到低能量不同，当吸收光时，我们从低能量开始,吸收能量到一个更高的能量。

麻省理工公开课 - 化学原理课程节选