Where do the water droplets come from?

Where did the fourth grade science beads come from?

Scientific concept: water vapor will condense into water when it is cold. Knowledge and skills: Know that the formation of water droplets is related to water vapor and low temperature.

Many small water droplets were observed on the outer wall of the plastic cup containing ice cubes. Think about where the water droplets come from and explain. According to the existing knowledge and experience, the source of small water droplets on the outer wall of plastic cups is analyzed and judged. Through experiments and analysis, the relationship between the formation of small water droplets on the outer wall of plastic cups and the ice cubes in the cups was explored. According to the new evidence, the causes of water droplets are explained reasonably.

Emphasis and difficulty in teaching: experience the process of hypothesis-analysis-re-hypothesis. This paper discusses the relationship between the formation of small water droplets on the outer wall of plastic cups and the ice cubes in the cups.

The change of the concept of "cup wall oozing": let the students who have opposition and support talk about his reasons.

Change of concept: discussion: put ice cubes in the bottle, cover the bottle cap and clean the water droplets outside the bottle. What do you find after observing for a period of time? Conclusion: The water drops on the outer wall of the ice cup will not overflow from the mouth of the cup.

The concept of "ice meets the rim of the cup and becomes water" has changed: after adding ice to the bottle, the outer wall of the quilt will be wiped clean. Observation: 2 minutes to see if there are any water drops on the outer wall of the quilt. Conclusion: The water drop on the outer wall of the glass is not the water formed by the melting of ice in the glass.

Thinking: Does the ice in the cup have anything to do with the formation of water droplets? Conclusion: Ice is related to the formation of water droplets, and cold and hot meet.

Extension: The water drop on the outer wall of the glass is not the water formed by the melting of the ice in the glass, but related to the ice in the glass. So where did the water droplets come from and how did they form?

There are many dewdrops on the grass in the late summer morning. Do you know how these dewdrops are formed?

There is water vapor in the air. Why does water vapor form water droplets when it meets a glass wall with ice, but not when it meets a glass wall without ice?