教学目标 :1 .认识液体、气体、固体都有热胀冷缩的性质 ,热胀冷缩性质在生产、生活中有广泛的应用。2 .学会设计和操作气体有热胀冷缩的实验。3.培养综合概括的能力和留心观察周围事物 ,主动探究的习惯。课前准备 :1 .教师演示材料 :热喷泉实验装置、瘪乒乓球、烧杯、热水、投 Teaching Objectives: 1. To understand the liquid, gas, solid have the nature of thermal expansion and contraction, thermal expansion and contraction properties in the production, life has a wide range of applications. Learn how to design and operate the experiments of gas expansion and contraction. 3. To develop a comprehensive ability to summarize and observe the things around, take the initiative to explore the habit. Pre-class preparation: 1. Teacher presentation materials: hot fountain experimental device, deflated table tennis, beaker, hot water, cast