Because only atomic hydrogen has that set of lines which means I could then take the spectra of gas phase species and use that information to identify.

我在这抬头看看然后离开，那就是氢原子,那就意味着,我可以测定,气相种类的光谱并且运用那个信息来鉴定。

麻省理工公开课 - 固态化学导论课程节选