Introduction
Before trying to attempt to answer the NCERT exercise questions, you should have a thorough understanding of class 6 Science chapter 11 i.e. ‘Air Around Us‘.
If you haven’t understood the chapter yet, then worry not you can go through it easily and develop a crystal clear understanding of various concepts from our notes whose link has been provided below.
NCERT Exercise Questions & Answers
Que. 1 What is the composition of air?
Ans. 1 Air is a mixture of various gases (nitrogen, oxygen, argon, carbon dioxide, etc.), water vapours, smoke, dust particles, etc.
Que. 2 Which gas in the atmosphere is essential for respiration?
Ans. 2 Oxygen gas in the atmosphere is essential for respiration.
Que. 3 How will you prove that air supports burning?
Ans. 3 We can prove that air supports burning with the help of a small experimental activity.
- We will take two candles of equal length and fix them on a table.
- Then we’ll light up both candles and cover one of them with an inverted glass tumbler. And, we will observe them.
- The candle that was covered was extinguished, whereas the other one continued burning.
The candle was extinguished because the component inside of the glass tumbler, which supports burning, is limited. Most of the components are used to burn candles. However, the other candle is getting a continued supply of air, hence it’s still burning. This component of air, which supports burning, is known as oxygen.
Que. 4 How will you show that air is dissolved in water?
Ans. 4 We can show/prove that air is dissolved in water with the help of a small experimental activity.
- We will pour some water into a metal container and put it on a stove.
- Then we’ll start heating the water slowly.
- Before the water begins to boil, we will get to see some small bubbles forming inside the container.
- Well, these bubbles come from the air dissolved in water and when you heat the water they start to escape.
Que. 5 Why does a lump of cotton wool shrink in water?
Ans. 5 The lump of cotton wool shrinks in water because the air that is present among the gaps of cotton fibres gets replaced by water which makes the fibres stick together and makes the wool heavier.
Que. 6 The layer of air around the Earth is known as______.
Ans. 6 The layer of air around the Earth is known as the atmosphere.
Que. 7 The component of air used by green plants to make their food, is _______.
Ans. 7 The component of air used by green plants to make their food, is carbon dioxide.
Que. 8 List five activities that are possible due to the presence of air.
Ans. 8 Five activities that are only possible because of the presence of air are:
- Photosynthesis by plants.
- Burning of fuel (wood, coal, petroleum, etc.).
- Flying of birds and kites.
- Pollination and seed dispersal.
- Breathing and respiration by plants and animals.
Que. 9 How do plants and animals help each other in the exchange of gases in the atmosphere?
Ans. 9 As we all know plant make their food by the process of photosynthesis by using the carbon dioxide gas from the atmosphere and in this process, they also produce a whole lot of oxygen as well. They only use a very small chunk of this produced oxygen for their respiration and release most of it back into the atmosphere for us to breathe and respire.
The balance of oxygen and carbon dioxide in the atmosphere is maintained through respiration in animals and plants and by photosynthesis in plants. And, this is how plants and animals help each other out in the exchange of gases in the atmosphere.
References & Credits
- Class 6 Science NCERT Textbook
- Image by Brigitte Werner from Pixabay
Thank You for Choosing Sciक्षक ❤️
Sciक्षक