Air around us class 6 notes
• pollution: contamination of the environment by dirt and harmful substances
• Atmosphere: A thick blanket of air surrounding the earth’s surface
• wind: moving air
• photosynthesis: a process used by green plants manufacture their food
• water vapour: the gaseous components present in the air
• air: a form of matter which has mass and occupies space
• carbon dioxide: a gas produced by the burning of fuels and by the organisms during the process of respiration.
• respiration: a life process used to produce energy to do work.
POINTS TO REMEMBER
• Air is present all around us.
• Air is essential for all living things.
• Air is an important natural resource. No life is possible without air.
Uses of air
Oxygen and carbon dioxide balance
• Water contains dissolved air. Aquatic plants and animals derive oxygen from the dissolved air.
• Air helps in breathing, burning and respiration.
• Moving air is called the wind. Air is invisible but we can feel its presence.
• Nitrogen is an important constituent of proteins required for body growth.
• Nitrogen, being almost inert, is used for packaging chips and another foodstuff.
The air around us class 6 notes
Multiple Choice Questions
1. Which of the following gas is not found in the atmosphere?
(d) Carbon dioxide
2. The largest amount of gas in the air is
(b) carbon dioxide
3. The gas released by the green plants during photosynthesis is
(c) carbon dioxide
4. Air is considered to be
(a) a compound
(b) a solvent
(d) an element
5. The component of air which is utilised by the plants in respiration is
(a) carbon dioxide
(d) water vapour
6. The envelope of air around earth’s crust is called
(c) carbon dioxide
7. Water is found in the air in the form of
(a) water vapour
8. The air over industrial cities has usually higher amount of one of the following components than normal air
(b) Carbon dioxide
9. The air in motion is called
10. Plants obtain nitrogen from
1. (b) 2. (a) 3. (b) 4. (c) 5. (a) 6. (b) 7. (a) 8. (b) 9. (c) 10. (c).
Fill in the blanks.
1. There is always some water vapour in the————- around us.
2. The layer of atmosphere extends up to—————kilometres.
3. Air is a———— of several gases.
4. The————— we live in is surrounded by a blanket of air.
5. The air surrounding the earth is called as————.
1. There is always some water vapour in the air around us.
2. The layer of atmosphere extends up to 300 kilometres.
3. Air is a mixture of several gases.
4. The earth we live in is surrounded by a blanket of air.
5. The air surrounding the earth is called as the atmosphere.
State whether ‘True’ or ‘False’
1. Air has a fixed percentage of water vapour.
2. Dust and smoke present in the air cause respiratory disease.
3. Nitrogen is the most reactive gas of the air.
4. Plants do not need oxygen.
5. All organisms require nitrogen for photosynthesis.
1. False, 2. True, 3. True, 4. False, 5. False.
Very Short Answer Questions
1. Name the gas used to fill the packets of potato chips?
2. Name various components of air.
3. What is the amount of nitrogen in the air?
4. Which of the two is present in a lesser amount in air – oxygen or nitrogen?
5. Which gas in the atmosphere is essential for respiration?
2. Oxygen, nitrogen, carbon dioxide, noble
gases, smoke particles, dust particles and water vapour.