精选优质文档-倾情为你奉上10级应用化学（2）班 郑禄春 BLessen 24 Chemical ReactionsConservation of mass and energy（质量与能量守恒）Two conservation laws（定律） apply to all chemical reactions: Energy can neither be created nor destroyed, and matter can neither be created nor destroyed. Thus the atoms taking part in a chemical reaction may be rearranged, but all the atoms present in the reactants must also be present in the products, and the total mass of the reactants must equal the total mass of the products.化
