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第十一课氮在自然界的循环氮肥的重要本课目的:使学生认识氮在自然界的循环及氮肥的重要性。检查学生知识:1.说出四种常见的硝酸盐,写出它们的分子式,说出它们的主要用途。2.说出硝酸盐的一般特性。3.黑火药中钾硝石起什么作用?用硝酸钠代替它行不行?为什么?
Lesson 11 Nitrogen Recycling in Nature The Importance of Nitrogen This lesson is to make students aware of the cycle of nitrogen in nature and the importance of nitrogen fertilizers. Check student knowledge: 1. Say four common nitrates, write out their formulas, state their main purpose. 2. Tell the general characteristics of nitrate. 3. What is the role of potassium nitrate salt in black gunpowder? Is it not possible to replace it with sodium nitrate? Why?