The sun is mostly hydrogen so we have a lot of absorption there, and here is sodium, the dark line in the yellow.

太阳主，所以我们在那里有很多吸收，这钠，黄的黑线。

The spectrum would look like this, and you'd always see this line spectrum from a heated hydrogen cloud or a compound that contains hydrogen.

光谱看起来像这样，你从加热的云或化合物中看到这条线谱。