一、根据教材内容选好演示器材 1.选择演示效果明显、可见度大的器材。演示实验的过程和现象要保证让全班学生都能看到,选择的器材要能清楚地显示出需要观察的现象。如《气体热胀冷缩》,选择仪器时,我用250ml大烧瓶,在瓶口上套一个红色气球。当气体受热时,气球鼓起来,气体遇冷时,气球变瘪。由于仪器大,观察对 First, according to the textbook content selected demo equipment 1. Select the demonstration effect is obvious, visibility of large equipment. Demonstration of the process and the phenomenon of experiment to ensure that all students can see the class, the choice of equipment to be able to clearly show the need to observe the phenomenon. Such as “gas thermal expansion and contraction”, select the instrument, I use 250ml flask, set a red balloon on the bottle. When the gas is heated, the balloon bulges, and when the gas cools, the balloon becomes deflated. Because of the large instrument, observe right