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“自然界的水”这一部分内容知识点较多,同学们可以通过五个方面来学习和理解水及其性质。一、一个重要的化学性质在通电条件下,水发生分解反应生成氢气与氧气。化学式是2H_2O通电2H_2↑+O_2↑。二、两种水的鉴别,净化水时两种物质的作用1.生活中的水分为硬水和软水,硬水是含有较多可溶性钙、镁化合物的水;软水是不含或含较少可溶性钙、镁化合物的水。鉴别硬水和软水的方法有两种。
“Water in nature ” This part of the content more knowledge points, students can learn from five aspects and understand the nature of water. First, an important chemical properties In the power conditions, water decomposition reaction of hydrogen and oxygen. Chemical formula is 2H_2O Power 2H_2 ↑ + O_2 ↑. Second, the two water identification, the role of the two substances when purifying water 1. Living water is hard and soft water, hard water is more water containing soluble calcium, magnesium compounds; soft water is free or contains less soluble calcium , Magnesium compound water. There are two ways to identify hard and soft water.