九年义务教材的化学实验分为课堂演示实验、学生实验和家庭小实验三项内容。前两项一般都是由教师参与在课内完成的实验，而后一项实验是学生在课外独立完成的实验。教材这样编写的目的，显然是让学生在课外通过学习科学家的研究方法，自己去感受、探索新知识，在新情境中解决 The chemical experiment of nine-year compulsory teaching materials is divided into three parts: classroom demonstration experiment, student experiment and family experiment. The first two items are generally performed by teachers in the experiment completed in the class, and the latter is the experiment that students complete independently outside of class. The purpose of this compilation of textbooks is obviously to allow students to learn, explore new knowledge, and solve problems in new situations by learning scientists’ research methods outside of class.