Black Friday: lifetime access is on a special offer in the app, until November 30. Black Friday: special offer on lifetime access, until November 30. Download
화학루미네슨스는 화학 반응에서 빛을 방출하는 현상입니다.hwahakruminesseunseun hwaehak ban-eungeseo bich-eul bangchulhaneun hyeonsang-imnida.Chemiluminescence is the phenomenon of emitting light during a chemical reaction.