一、说大纲《空气的成分》是在低年级学生学习空气的基本性质的基础上 ,知识进一步的深化。大纲要求指导学生知道空气不是一种单纯的气体 ,是由多种气体混合而成的。培养学生的观察能力、模拟实验能力、动手能力、分析综合能力。能根据空气中混合物的性质差异分析空气的成分。 First, say the outline of “the composition of the air” is the further deepening of knowledge on the basis of the basic nature of the learning air for the lower grades. The outline calls for students to be aware that air is not a mere gas and is a mixture of gases. Develop students' abilities of observation, simulation and experiment, ability and analysis of comprehensive ability. The composition of the air can be analyzed according to the nature of the mixture in the air.