The chapter “Air its Uses and Pollution” is Chapter 20 from Let’s Look Around and Learn Environmental Studies for students of Class 5th of JKBOSE. This post is precisely about Air its Uses and Pollution Class 5 EVS Question Answers. In my last post, you read about Sunita in Space Class 5 EVS Chapter Notes. Let’s get started with today’s post:
Air its Uses and Pollution Class 5 EVS Question Answers
The chapter “Air its Uses and Pollution” details students about the properties of air, its uses and pollution of air. Air is very useful for the survival of living things on earth. We need to keep it clean and fresh.
Think and Answer Page No. 182.
I. Fill in the blanks. Choose the right word/ words from the box:
|harmful, air exerts, pressure, nitrogen, space, oxygen, mixture, no, weight|
- Air has ________ shape of its own.
- Air is a ________ of gases.
- The major constituents of air are ________ and ________.
- Air occupies ________ and has ________.
- Pichkari works on the principle that ________.
- Polluted air is ________ to health.
- Air has no shape of its own.
- Air is a mixture of gases.
- The major constituents of air are nitrogen and oxygen.
- Air occupies space and has weight.
- Pichkari works on the principle that air exerts pressure.
- Polluted air is harmful to health.
II. Give scientific reasons
- Air exerts pressure but we do not feel it.
Ans. Air exerts pressure due to its weight. We do not feel it because it acts equally in all directions.
- Air is a mixture of gases but to us, it appears to be a single gas.
Ans. Air is a mixture of gases like nitrogen, oxygen, carbon dioxide, neon, helium, hydrogen etc. But visually there’s nothing, I mean that ‘air’ is a highly transparent gas. It is the main gas due to which air appears to us as a single gas.
- Air has no shape of its own.
Ans. Air has no shape of its own. It is flexible because molecules of the air have large spaces in them and can move in any place and direction. It takes the shape of the container in which it is enclosed.
III. State whether True or False for each statement
- Air is a mixture of gases. ( )
- Air does not occupy space. ( )
- Air exerts pressure. ( )
- Air takes the shape of a container. ( )
- Carbon dioxide is needed for green plants to prepare their food. ( )
- Polluted air is suitable for breathing. ( )
- Air is a mixture of gases. (True)
- Air does not occupy space. (False)
- Air exerts pressure. (True)
- Air takes the shape of a container. (True)
- Carbon dioxide is needed for green plants to prepare their food. (True)
- Polluted air is suitable for breathing. (False)
IV. Tick (1) the correct answers
- Air consists of:
(a) Oxygen only
(b) Nitrogen only
(c) Carbon dioxide only
(d) All the above gases.
Ans. (d) All the above gases
- Fertilizers are prepared from:
(d) Rare gases.
Ans. (a) Nitrogen
- A gas used in brightly coloured lights is:
Ans. (c) Neon
- The gas used in filling balloons is:
(d) Carbon dioxide.
Ans. (b) Helium
- Pollution of air is due to:
(a) Carbon dioxide is given out by human beings and animals.
(b) Smoke has been given out by automobiles, factories, etc.
(c) Cutting of the green plants.
(d) Growing fewer trees and plants.
Ans. (b) Smoke has been given out by automobiles, factories, etc.
V. Answer the following questions
- Mention two properties of air pressure.
Ans. Properties of air pressure. –
(i) Air pressure can expand certain bodies.
(ii) Air pressure can move liquids.
- Describe an experiment to prove that air has weight.
Ans. Experiment to prove that air has weight.
Fill two balloons with air so that both of them are equal in size. Tie the mouths of the two balloons with strings of the same size. Now hang the balloons one on each side of the stick as shown in fig. (a). Hold up the string at the centre.
The stick remains horizontal and the balloons are balanced. Now prick one of the balloons with the pin and allow air to escape. By doing so this end will go up and the other end will come down as shown in fig. (b). The balloon filled with air is heavier than the balloon which has no air. This shows that air occupies space and has weight.
- Describe an experiment to prove that air exerts pressure.
Ans. Experiment to prove that air exerts pressure.
Take a glass tumbler and fill it with water. Cover the tumbler with thick cardboard with your hand. Hold the tumbler with the other hand and carefully turn the | tumbler upside down.
We see that cardboard does not fall. It is because that air exerts upward pressure on the cardboard and so the cardboard and water do not fall. So it is clear that air exerts pressure.
- State the names of five rare gases in the air.
Ans. Rare gases present in the air are Helium, Neon, Argon, Krypton, and Xenon.
- Cite some examples which are based on the principle that air exerts pressure.
Ans. Following are the examples which are based on the principle that air exerts pressure:
(i) Drawing liquids up in a straw.
(ii) An injection syringe.
(iii) A medical dropper.
(iv) An ink-filler.
(v) A fountain pen.
(vi) Common lift pump.
- How does the medicine dropper work?
Ans. Dip the open end of the dropper into the liquid medicine and now the rubber bulb is pressed. The air from the tube of the dropper is forced out and the air pressure inside it is reduced. The outside air pressure presses the liquid medicine into the tube of the dropper.
- Name the gadgets in daily use which make use of air pressure.
Ans. Siphon, a fountain pen, an injection syringe, a medical dropper, a common lift pump.
- Give an experiment to show how air pressure helps to push down or lift liquid in the straw.
Ans. Experiment. Keep one end of the straw in the drink and suck through the other end. By doing so, some air is removed from the tube and air pressure inside it is reduced. But the outside pressure acting on the outer surface of the drink forces it up into the straw.
- How do you feel the air around you?
Ans. We feel the presence of air around us. when our clothes begin to flutter and small bits of paper move from one place to another and also from the pressure on our body and cooling effect of air on us.
- State the uses of nitrogen and oxygen.
Ans. Uses of nitrogen.
(i) It is required for the normal growth and development of plants.
(ii) It serves to dilute the highly active gas, oxygen.
(iii) Fertilizers are prepared from nitrogen.
Uses of Oxygen.
(i) It is used by all living organisms for respiration.
(ii) It is essential for burning.
- State the uses of carbon dioxide.
Ans. Uses of carbon dioxide.
(i) It is used by green plants to prepare their food.
(ii) It is filled with soft drinks.
- State two uses of Siphon. Ans. Uses of siphon.
(i) It helps in taking out liquid from a higher level to a lower level.
(ii) The scooter or bike mechanics take out petrol by using the method of siphon.
- What is air pollution?
Ans. Air pollution. The contamination of natural air with harmful substances and poisonous gases makes the air impure. This is called air pollution.
- What are the different causes of air pollution?
Ans. Causes of Air Pollution. Various causes of air pollution are:
(i) Burning coal, wood, kerosene, petrol, diesel etc.
(ii) Exhaust gases from automobiles. (iii) Smoke from factories.
(iv) Smoke, dirt and dust raised by heavy traffic
(v) Dirt and dust from certain mines.
- List some ways to control air pollution.
Ans. Control of air pollution.
The pollution of air can be controlled in the following ways.
(i) Use smokeless sources of energy, like solar energy, wind energy etc.
(ii) Install very tall chimneys in the factories.
(iii) Grow more trees.
That’s all we have about Air its Uses and Pollution Class 5 EVS Question Answers. Hope you got all your answers. Do share your views about this post in the comment section.
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