The Whys of Weather - Rain

 

 

 

The sky gets cloudy. Clouds get darker and darker. The sun disappears, and soon drops of water start falling from the sky. But have you ever wondered why? What makes the rain fall?

First, you have to understand condensation. On a hot day, have you ever had a glass of a cold drink and noticed the outside of the glass getting wet? How does this happen? There is water in the air that you cannot see. It’s in the form of a gas called water vapor. The cool drink cools the air around the glass. This causes the water vapor around the glass to turn into liquid water on the glass. Little water droplets form and make the outside of the glass wet. This is an example of condensation. Condensation is the process by which water vapor in the air changes into liquid water.

There is always water vapor in the sky. After water vapor turns into liquid water, cloud droplets might form. This happens when the liquid water sticks to specks of dust, ice crystals, or even other liquid water droplets. Many cloud droplets form a cloud.

In the cloud, millions of cloud droplets make a raindrop. When raindrops become too heavy to stay up in the cloud, they fall to the ground as rain. Rain is a form of precipitation. Other forms of precipitation include snow and hail.

Comprehension Questions

1. What is the process by which water vapor in the air changes into liquid water? 

1. liquidation 
2. perspiration 
3. condensation 
4. precipitation 

2. Why does the author describe the condensation of water droplets on the outside of a cold glass? 

1. to explain how rain is different from snow 
2. to show how water evaporates into the air 
3. to give an example of how water is unpredictable 
4. to compare it to condensation of water in the sky 

3. If water did not condense into clouds in the sky, which of the following statements would be true? 

1. It would not rain or snow. 
2. There would be no sunshine. 
3. It would rain all the time. 
4. There would be snow but not rain. 

4. Read the following sentences:

“There is always water vapor in the sky. After water vapor turns into liquid water, cloud droplets might form. This happens when the liquid water sticks to specks of dust, ice crystals, or even other liquid water droplets. Many cloud droplets form a cloud.”

Based on these sentences, what does the word “form” most nearly mean? 

1. to speed up 
2. to create 
3. to shape or structure 
4. to destroy 

5. What is a main idea of this text? 

1. Condensation is a key part of the process that forms clouds. 
2. A cool drink cools the air around the glass, causing little water droplets to form outside of the glass. 
3. When raindrops become too heavy to stay up in the cloud, they fall to the ground as rain. 
4. There are different types of precipitation. 

6. Why does condensation form on the outside of a drinking glass? 

(written answer)

7. Why is condensation necessary for clouds to form? Use evidence in the text to support your answer. 

(written answer)

8. Choose the answer that best completes the sentence.

__________ water vapor turns into liquid water, cloud droplets might form. 

1. Although 
2. Before 
3. After 
4. However