*,*,*,*,*,*,*,*,*,*,*,*,*,*,*,*,*,*,*,*,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,根据（五四学制）新青岛版四年级科学下册教材制定,21.,雨和雪,根据（五四学制）新青岛版四年级科学下册教材制定21.雨和雪,学生准备：课前搜集有关雨和雪的有关资料。,教师准备：准备实验器材:酒精灯、火柴、三脚架、石棉网、装半杯水的烧杯等。,活动准备,学生准备：课前搜集有关雨和雪的有关资料。活动准备,活动过程,活动过程,活动过程：观察露,活动过程：观察露,活动过程：观察露,活动过程：观察露,假设,根据事实和科学理论，对研究问题的规律或原因做出一种推测性的论断或假定性解释就是在,假设,。,活动过程：观察露,假设 根据事实和科学理论，对研究问题的规律或原因,活动前,设计一个实验，模拟雨的形成过程,。,活动过程：观察露,活动前设计一个实验，模拟雨的形成过程。活动过程：观察露,分组讨论实验方案,1.组装好实验器材，在平底烧瓶中放入一些水。,2.在烧杯内放一个冰袋，让烧杯底部温度更低。,3.点燃酒精灯，用外焰加热平底烧瓶中的水。,4.过一段时间，观察现象。,活动过程：观察露,分组讨论实验方案1.组装好实验器材，在平底烧瓶中放入一些水。,实验结论,水水蒸气,水,活动过程：观察露,实验结论水水蒸气水活动过程：观察露,实验小结,要设计模拟某种自然现象的实验，首先要思考,这种现象与什么物体有关系,，,是在什么条件下发生的,，然后思考,怎样才能得到这些物体,，,怎样创造所需的条件,。,由于雨是水蒸气受冷凝结成的，因此就要思考如何得到充足的水蒸气,，,怎样使水蒸气受冷,？可以考虑,加上冰袋或者冷水袋使水蒸气凝结成的小水珠，不断增多汇成水滴降落下来。,活动过程：观察露,实验小结 要设计模拟某种自然现象的实验，首先要,活动过程：观察露,活动过程：观察露,活动过程：观察露,活动过程：观察露,活动过程：观察露,活动过程：观察露,雨,雪,活动过程：观察露,雨雪活动过程：观察露,拓展活动,拓展活动,