NCERT Solutions for Class 2 Science Chapter 9 Air all question answers and practice assignments updated for CBSE and State board students session 2022-2023 free to download. In Class 2 Science chapter 9, student will learn about the components of air present in our atmosphere and learn the way to keep it clean. Question answers given in exercises are important for revision.
Study Material for Class 2 Science Chapter 9
What Does Air Contain?
All living things need air to breathe. Air is all around us. We cannot see or touch air. But we can feel it when it moves. Air contains many things. Let us learn about them.
Air contains gases, water vapour, smoke and dust. When you hang your wet clothes out in the sun, your clothes get dried. Where does the water of the clothes go? It turns into water vapour and mixes with air. Similarly, water of rivers, lakes and ponds changes into water vapour due to heat of the sun.
Fresh air does not contain smoke, dust or germs. So, we should breathe in fresh air. It keeps us healthy. Plants make air fresh. We should have morning walk in the garden. We should grow plants near our house. We should keep windows of our house open to let in fresh air. Do not cover your face when you sleep.
Note: Air is a mixture of gases like nitrogen, carbon dioxide, oxygen, etc.
Dirty air contains smoke or germs. Factories and vehicles release smoke. It makes fresh air dirty. A sick person releases germs while coughing or sneezing. These germs mix with air. When we breathe in this air, we also fall sick. So, we should cover our mouth when we cough or sneeze.
Moving air is called wind. Slow wind is called breeze. It is pleasant. A strong or fast wind can blow away things like clothes, paper and loose soil. A very strong wind is called storm. It can uproot trees. It can also damage our houses.
Wind Is Useful
Wind moves the fans of a windmill. A windmill is used to run water pumps. Wind also helps sailboat to move on water. Wind carries seeds of plants to new places. This way the new plants get more space to grow. Wind also helps us to fly kites.
Direction of The Wind
A weathercock tells us the direction of the wind. It is placed on the top of the house. The beak of the cock shows the direction in which the wind is blowing.
Wind is Useful
Wind is useful to us in many ways. Wind helps us in flying kites and winnowing. Wind helps gliders move and boats sail. Strong winds help in running windmill.
Water vapour is mixed with air. So we can say, air has water vapour.
1. Air is everywhere.
2. We cannot see it but we can feel it.
3. People, animals and plants need air to live.
4. Air contains gases, water vapour, smoke and dust.
5. Smoke comes from fire, factories, cars and buses etc.
6. The change of water into water vapour is called evaporation.
7. We should breathe in fresh air.
8. Plants make air fresh.
9. Fresh air is clean and keeps us healthy.
10. Moving air is called wind.
11. Wind is useful to us in many ways Wind has direction.
Select correct option for given questions:
Which of the following does not need air?
What does air not contain?
What makes air fresh?
Which of the following is dangerous?
Fill in the blanks with suitable words given in the bracket: (live, life, breeze, cover, smoke)
1. We cannot _____________ without air.
2. There can be no _____________ without air.
3. Factories and vehicles release _____________.
4. We should _________ our mouth while coughing or sneezing.
5. Slow wind is called _____________.
1. We can feel air when it moves.
2. Smoke comes from factories and vehicles.
3. Germs cannot make us sick.
4. We should not cover our face while sleeping.
5. Plants make the air dirty.