光化学反应 guānghuàxuéfǎnyìng photochemical reaction Origin Definitions Defs Strokes Stroke Words Sentences Sents 光 guāng noun light light; ray; beam of light化学 化學 huàxué noun chemistry; chemical chemistry; chemical; the study of the structure, properties, and reactions of matter反应 反應 fǎnyìng nounverb chemical reaction a process in which substances undergo chemical or physical change