Very nice take on the theme! The sun & moon mechanic felt slightly tedious, since you need to switch to a different mode, drag something, switch back, and only then see the result, which breaks the problem-solving flow a little bit. At some of the “atomic” levels it’s really hard to see the further parts of it - it took me quite a while to make the gasoline molecule (see the screenshot). And, yeah, water, acid and gasoline are molecules, not atoms :)
Anyways, congrats with your submission, I quite enjoyed it! I’d be happy if you tried my game as well: https://lisyarus.itch.io/color-fractory