一、化学能与热能1.化学键与化学反应中能量变化的关系化学反应的本质是旧化学键的断裂和新化学键的形成,前者需要吸收能量,后者需要放出能量,两者的差即为反应中的能量变化.例1下列说法正确的是()(A)物质发生化学反应时放出的热量来源于对反应的加热 First, the chemical energy and heat 1. Chemical bonds and chemical reactions in the relationship between energy changes Chemical reactions are the essence of the old chemical bond fracture and the formation of new chemical bonds, the former need to absorb energy, the latter need to release energy, the difference between the two is the reaction In Example 1 The following statement is correct () (A) The material in the chemical reaction of the heat released from the reaction of heating