There were glow sticks at Laura's party! I've always known that flexing the case breaks a chemical container inside allowing two chemicals to mix. Looking up the details here has got me doing some thinking. It says that the reaction is exergonic. This seems to be because the reaction is at constant temperature. The graph seems similar to the one I taught for exothermic reactions but they would release heat and presumably the temperature wouldn't remain constant. The energy released seems to excite a dye compound, meaning that the electrons go up energy levels. They de-excite by releasing a photon and if the dye is chosen so that the energy levels produce photons that lie in the visible range, we have a glow stick. Would we still call them glow sticks if there were photons released but not visible to the human eye?
