教学目标 :１ 要求学生知道二氧化碳的性质 ,了解二氧化碳的用途 ;２ 培养学生的实验能力和推理能力 ;３ 使学生体会到人只有了解自然 ,才能更好地利用自然。教学重点、难点 :重点是指导学生做好研究二氧化碳性质的几个实验。难点是使学生理解二氧化碳比空气重这个性质。教学准 Teaching Objectives: 1. Require students to know the nature of carbon dioxide and to understand the uses of carbon dioxide. 2. To develop students' experimental and reasoning skills. 3. To enable students to understand that people can make better use of nature by understanding nature. Teaching focus, difficulties: focus is to guide students to do a good job of several experiments on the nature of carbon dioxide. The challenge is to make students understand that carbon dioxide is heavier than air. Teaching standards