教学生形象地理解“水蒸发就是液体的水变成气体的水蒸气飞散到空中去了”这句话,既关系到对于“白气”的认识,又关系到对云和雾成因的理解;“空气中含有许多看不见的水蒸气,空气变湿了”,从而又引出关于空气湿度的概念。所以让学生亲自感知一下飞散到空气中去的水是很有好处的。据此我设计了一个“收集水蒸气的课外实验,作法是每个学生找一只不漏气的塑料袋,一个大小适当的容器(罐头盒、硬纸盒、小花盆均可),里面装上湿土。实验 Teaching students to understand the image of “water evaporation is the liquid water into a gas water vapor flying into the air,” this sentence, both related to the “white gas” understanding, but also related to the understanding of the causes of clouds and fog; “There is a lot of invisible water vapor in the air and the air is getting wet,” drawing the notion of air humidity. So it is good for the students to personally sense the water that has been scattered into the air. Based on this I designed a "Extra-curricular experiment to collect water vapor by finding an airtight plastic bag for each student, a properly sized container (canned, carton, flowerpot) Install wet soil. Experiment