八年级科学下册第二章节空气与生命第一节空气课件浙教版.ppt

《八年级科学下册第二章节空气与生命第一节空气课件浙教版.ppt》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、我们一起学习Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.课前小比拼:请同学们屏住呼吸,看谁坚持的时间最长?为什么坚持不到一两分钟就坚持不住了呢?生命活动离不开空气Evaluationonly.CreatedwithAspose

2、.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.大胆的想象:如果我们生活的地球上没有空气，那我们的地球会是什么样子？Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011A

3、sposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.你能收集一瓶教室里的空气吗？我来动动手:Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProf

4、ile5.2.0.0.Copyright2004-2011AsposePtyLtd.空气看不见也摸不着，你能举一些生活现象证明空气的存在吗？(小组讨论回答)我最有办法:Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.空气中有哪些物

5、质？我的猜想：空气中可能含有氧气空气中可能含有水蒸气空气中可能含有二氧化碳……我们来探究:提出问题：设计实验：Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.三条信息:１，二氧化碳能使澄清石灰水变浑浊２，氧气可以助燃，氧气的浓度越

6、大燃烧越旺盛３，白色无水硫酸铜遇水会变蓝色Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.这说明空气中含有_____________。含量较_______(多/少)。1.用大针筒把空气压进石灰水中。石灰水是否会变浑浊?______

7、_____。变浑浊的速度怎么样?___________。变浑浊比较慢二氧化碳少结论:我们来探究:空气中可能含有二氧化碳Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright200