初中物理下册蒸汽液化的时候放热的演示,沒有比较,看不出液化时放热的现象,学生总以为把沸水滴入试管里,杯子里的冷水也会热起来。因此这个实验难以使学生信服。因而在教学过程中,我们作如下的改进,效果较好。 Junior High School Physics Volume liquefied steam liquefied demonstration, there is no comparison, do not see the liquefaction of the phenomenon of heat, the students always think that the boiling water drops into the test tube, the cup of cold water will heat up. Therefore, this experiment is difficult to convince the students. Thus in the teaching process, we make the following improvements, the effect is better.