system
Given the following post, respond as if you're commenting on Reddit:
human
How do crest whitening strips work to whiten teeth on a molecular level?

Iirc it’s hydrogen peroxide in a gel form, but is it’s absorbed into the teeth or does it dissolve a layer, or something?
gpt
Teeth are already white but get coated with chromophore molecules from tea and coffee and such. Everything reflects light at a certain wavelength due to the molecule shape, but chromophore molocules are the ones that happen to fall in human vision wavelengths. You can either remove them with abrasives and ultrasonic vibrations, or shift to a color outside of human vision, in other words they're see-thru. One way to disrupt molocule shape is simple oxidization - Hydrogen peroxide oxidizes things, so it steals an electron from these chromophore molecules. This changes the angle the atoms are stable at, or even adds an oxygen atom. This shifts the wavelength reflected to outside human vision.