物质在固态、液态和气态之间的互相变化,是我们在日常生活中时常接触到的一些现象;即使是初中学生,对于这些现象也是此较熟悉的。这在我们的教学上显然就是一个有利的条件。因此,在“物态的变化”这一课题中,如果我们能够结合学生已有的经验,多从演示实验出发来介绍其中的一些基本概念,例如熔 Changes in the physical, liquid and gaseous states of matter are some of the phenomena that we are exposed to in our daily lives; even junior high school students are more familiar with these phenomena. This is clearly a favorable condition in our teaching. Therefore, in the subject of “the change of state”, if we can combine the existing experience of the students, we introduce some basic concepts from the demonstration experiments, such as melting