Uranium is one of the most notorious elements — it's gotten a pretty bad rap due to its tendency to show up in nuclear weapons. Also, it's kind of radioactive. That's probably why it's such a great element to show your support for in t-shirt form. Woot! has uranium tees that pay tribute to this crazy, 92-proton element. But maybe you're into having molecules on your tee, and you want them to do more than look pretty. Maybe you want them to actually undergo a chemical reaction right there on your chest. That's where hypercolor tees come in — their dye changes color as it heats up next to your skin. Though hypercolor tees enjoyed a brief popularity in the 1980s, they passed out of trendiness (partly because if you washed them in really hot water, they lost their hyperness). But now 80s-retro franchise American Apparel is selling them by the assload. Unfortunately, none of the American Apparel tees are as cool as this one, below, a beta test design by Steve Hancox. You heat it up, and the sun comes out. So how does it all work?
Of course, Wikipedia has a scientific explanation for this ephemeral pop culture phenomenon. And if you really need a specialized molecule, you can just stop by Molecule Wear — they have some of the coolest molecules.