第十七课

17   Water vapor condensation水蒸气凝结

1. In the early morning, the small dewdrops on the leaves are crystal clear and清晨，叶片上的小露珠晶莹剔透，

2. like a sparkling little pearl.像一颗颗璀璨的小珍珠。

3. Where do these little dewdrops come from?这些小露珠是从哪里来的呢？

4. Material kit: mirror, etc.材料包：镜子等

5. activity process活动过程

6. How are the little drops of water formed?小水珠是怎样形成的？

7. I guess ------我猜想······

8. let's try it this way.我们这样试一试。

9. Thought navigation思维导航

10. What are the same conditions and different conditions in the experiment?实验中的相同条件和不同条件分别是什么？

11. What is the difference between the phenomena produced on a cold glass sheet and a hot glass sheet?冷玻璃片和热玻璃片上产生的现象有什么不同？

12. What is the reason for the formation of small water droplets?小水珠形成的原因是什么？

13. method guide方法指导

14. When heating the glass with an alcohol lamp用酒精灯给玻璃加热时，

15. to move the glass要来回移动玻璃片，

16. so that the glass piece is evenly heated.让玻璃片均匀受热。

17. water vapor can turn into liquid water when it is cold, which is a condensation phenomenon.水蒸气遇冷可以变成液态的水，是一种凝结现象。

18. Look for condensation in your life.找一找生活中的凝结现象。

19. I also know我还知道

20. Extension activities拓展活动

21. In winter, there are often small water droplets on the inner wall of the car glass.冬季，汽车玻璃内壁上常结有小水珠，

22. affect the driver's vision.影响司机的视线。

23. How to prevent small droplets of water from appearing?怎样防止小水珠出现？

24. Look up the information and tell us what you can do.查阅资料，说说你的办法。