霜常常出现在秋冬两季的早晨,是近地面空气中的水蒸气在物体表面上凝华的产物。虽然霜是学生比较熟悉的自然现象,八年级物理课本也多处提到过霜,但是学生并没有见过霜的形成过程,很难理解霜的成因。然而,学生对自然界中霜的形成过程有着浓厚的兴趣,若能利用身边的材料在课堂上成功地演示其形成过程,不仅能增加学生对物理知识的亲切感,激发他们的求知欲,而且对学生理解凝华概念和了解自然现象的形成过程都有宜处。 Frost often appear in the autumn and winter morning, is the product of the water vapor in the near-surface air on the surface of the object. Although frost is a natural phenomenon that students are familiar with, eighth grade physical textbooks also mentioned frost in many places, but students have not seen the formation of frost and it is difficult to understand the cause of frost. However, students have a keen interest in the formation of frost in nature. If they can successfully demonstrate the process of formation in the classroom by using the materials around them, they not only increase students' intimacy of physical knowledge and stimulate their thirst for knowledge, Students understand the concept of sublimation and understand the formation of natural phenomena are appropriate.