"Chemistry is-- huh." He's never actually had to explain it before. Not the entire concept. He runs Kyle through some of the finer points once in a while - guy's gotta learn somehow - but this is like coming across someone who doesn't understand... well, air.

"So it's a science. With it, we study the way that substances interact with each other right down to a molecular level. So... like. You bake, right? Well, baking is chemistry. You mix ingredients together, they interact with one another-- like how yeast makes bread rise, and baking soda makes volcanoes? Yeah. And the tricorder? Picks up on those molecules, and identifies them for us. Pretty awesome, right?"