Chemiluminescence (sometimes "chemoluminescence")'s the emission of light with limited emission of heat (luminescence), as the result of a chemical reaction. Given reactants A and B, with an excited intermediate ◊, » [A] + [B] → [◊] → [Products] + light For example, if [A]'s luminol and [B]'s hydrogen peroxide in the presence of a suitable catalyst we've: » luminol + H2O2 → 3-APA[◊] → 3-APA + light where: where 3-APA's 3-aminophthalate 3-APA[◊]'s… (More on Chemiluminescence)