Question

How would a spectrum help you learn what the atmosphere of Venus is made of?

Answer 1

certain levels of energy gives off colors. this is observed during laboratory experiments in many cases, such as color changes during a chemical reaction and color of precipitation, etc. so we can figure certain chemicals in the atmosphere of venus based on the prevalent color it has when comparing to the experiments we have here on earth.

Answer 2

Each molecule has its own unique set of energy levels that electrons can be in. That means molecules only absorb and emit light of certain specific colors that exactly match these special gaps. In fact, that's how all color works, it just happens that you can't see most light since the molecules in your eyeballs only have energy levels that match some. So we call that the visible spectrum, while other light like microwaves or wifi or radio waves are just light we don't have the molecules with the right gaps in energy levels to see! Fancy.