论文部分内容阅读
以往教《燃烧与灭火》是“牵”。特别是关于燃烧的三个条件,先让学生看图,哪些物体能燃烧,哪些物体不能燃烧,从而得出“可燃物”。再做实验,隔着铁片烤火柴,得出燃烧需要一定的温度,最后通过分析烧煤的炉子,得出燃烧需要空气中的氧。总之,一步一步牵着走,直奔结论。 今年教《燃烧与灭火》,我想应该真正让学生自己发现燃烧的条件,因此首先要在教学材料上下功夫,我设计了如下教学材料: 石头,砖块、细铁丝——非可燃物;煤块在酒精灯上燃烧,三五分钟看不出燃烧的迹象,但学生都知道煤是可燃物。木条次之,纸条见火就燃,而打火机射出很小的火花,可燃气体立即燃烧。还有常用的酒精灯。
In the past to teach “burning and fire fighting” is “pull.” Especially about the three conditions of combustion, let students see the map, which objects can burn, which objects can not be burned, resulting in “combustible.” Do experiments again, across the iron roasted matches, concluded that the combustion requires a certain temperature, and finally by analyzing the coal burning stove, concluded that the combustion of oxygen in the air. In short, go step by step, go straight to the conclusion. This year, teaching “Combustion and Extinguishing Fire”, I think we should really let the students discover the burning conditions themselves. Therefore, we must first make efforts in the teaching materials. I designed the following teaching materials: stones, bricks, fine wire - non-combustibles; coal The block burns on the alcohol lamp, 35 minutes can not see the signs of burning, but students all know coal is flammable. Strips second, the paper to see the fire, and lighters fired a small spark, combustible gas immediately burning. There are commonly used alcohol lamp.