Is this high school, or college that we're talking about? If college, I've got a suggestion. My junior year project was on nuclear magnetic resonance. I used an NMR apparatus to measure the spin-lattice and spin-spin relaxation times for a 5 minute curing epoxy, at different times in its curing process (spin-lattice and spin-spin relaxation times are just two constants characteristic of a material's chemical properties, which NMRs can easily measure). Perhaps you could measure these constants for some other chemical compound as you alter it in some way?