Air Around Us BOSEM Class 6 Science Solutions

Explore Class 6 Science Chapter ‘Air Around Us’ with key questions and answers. Understand the composition of air, the role of oxygen in respiration, the importance of nitrogen, and how air supports life on Earth. Ideal for exam preparation with extra questions and clear explanations.

Solutions for Air Around Us

Find comprehensive solutions for Class 6 Science Chapter ‘Air Around Us.’ Get detailed answers to key questions, and understand concepts like air composition, respiration, burning, and more. Perfect for exam preparation and concept clarity

Answer the following Questions

Q1. What is the composition of air?

Ans: Air is composed of water vapour, oxygen, nitrogen, carbon dioxide, dust, smoke, and other gases. Oxygen and nitrogen constitute 99%, and the remaining 1% is constituted by carbon dioxide, water vapour, and other gases.

Q2. Which gas in the atmosphere is essential for respiration?

Ans: Oxygen in the atmosphere is essential for respiration.

Q3. How will you prove that air supports burning?

Ans: Take two candles on a table. Light both candles. Cover one of the candles with an inverted glass tumbler. After some time, the candle covered by the glass tumbler is extinguished because the air supply is cut off, and the oxygen inside the glass tumbler, which supports burning, is used up by the burning candle. However, the other candle is getting a continuous supply of air, which supports burning. This shows that air supports burning.

Q4. How will you show that air is dissolved in water?

Ans: Take a container filled with water and heat it. After some time, we see tiny bubbles on the inner surface of the container. These bubbles come from the air dissolved in water. When we heat the water, the air dissolved in it escapes. As we continue heating, the water turns into vapour and finally begins to boil. This shows that air is dissolved in water.

Q5. Why does a lump of cotton wool shrink in water?

Ans: A lump of cotton wool shrinks in water because the space present in the fibres is occupied by air, which, when immersed in water, is replaced by water.

Q6. The layer of air around the earth is known as ……
Ans: Atmosphere.

Q7. The components of air used by green plants to make their food is…
Ans: Carbon dioxide.

Q8. List five activities that are possible due to the presence of air.
Ans:

1. Air plays an important role in the water cycle.
2. Air helps in the dispersal of seeds and pollination of flowers.
3. Birds and insects can fly due to the presence of air.
4. Air helps in the movement of aeroplanes, gliders and parachutes.
5. Burning of candles.

Q9. How do plants and animals help each other in the exchange of gases in the atmosphere?
Ans: Plants use carbon dioxide during photosynthesis and oxygen is released in the
atmosphere. Again animals use this oxygen released by the plant for respiration and
carbon dioxide is given out which is used by the plant again to make their food. In this
way, Oxygen and Carbon dioxide are balanced in the atmosphere. This shows the
interdependence of plants and animals in exchange of gases.

Extra Questions and Answers

Q1. When a bottle is inverted inside the water, water doesn’t enter the bottle but when the bottle is slightly tilted, water enters the bottle. Why?
Ans: The bottle is not empty, it is filled with air. When it is pushed in an inverted position, water
doesn’t enter as there is no space for air to escape. When the bottle was tilted, the
air was able to come out in the form of bubbles, and water filled up the empty space
that the air occupied.

Q2. Define atmosphere.
Ans: The atmosphere is the thin layer of air that surrounds the earth.

Q3. Why do mountaineers carry oxygen cylinders with them, while climbing high mountains?
Ans: As we move high in the atmosphere, the air gets rarer and the oxygen level in the
atmosphere decreases.

Q4. Name the component of air that supports burning.
Ans: Oxygen

Q5. Name the component of air that does not support burning.
Ans: Nitrogen.

Q6. Why do we suffocate in a closed room where material is burning?
Ans: Burning releases carbon dioxide and, as the burning continues there is an accumulation of
Carbon dioxide and depletion of Oxygen. Therefore, we suffocate in a closed room
where material is burning

Q7. Why do nostrils have fine hair and mucus?
Ans: Fine hair and mucus are present inside the nose to prevent dust particles from getting
into the respiratory system when we inhale air.

Q8. How will you show that air also contains dust particles?
Ans: During winter, we see a beam of sunlight filter through the tree and we notice
tiny particles floating in the air. These are the dust particles. This shows air also contains
dust particles.

Q9. Why do Earthworms come out of the soil after heavy rain?
Ans: Animals like earthworms use the air present in the soil pores and in the burrows and
holes for respiration. When it rains heavily, water fills up all the space occupied by the
air in the soil. So, they come out from the soil for respiration.

Q10. Why do factories have long chimneys?
Ans: Burning of fuel produces smoke that contains gases and dust particles that are harmful
to us. In order to take the harmful smoke and gases away from our noses, so that
we don’t breathe in, factories have long chimneys.

Q11. What is weather cock?
Ans: A weather cock is an instrument that shows the direction of wind.

Q12. What is a windmill? Give two uses of windmills.
Ans: Windmill is a device that converts wind energy into mechanical energy. The two uses of
windmills are:

a. To produce electricity.
b. To draw water from tubewells.

Additional Extra Questions and Answers

Q13. Why do we say that air is a mixture and not a compound?
Ans: Air is a mixture because it consists of different gases like nitrogen, oxygen, carbon dioxide, and others mixed physically, without any chemical bonds between them. Each gas retains its individual properties in the mixture.

Q14. Explain why it is easier to burn a candle in open air than in a closed container.
Ans: In open air, oxygen is continuously available, which supports burning. In a closed container, however, the oxygen supply is limited, and once it’s used up, the flame extinguishes.

Q15. How is the presence of oxygen in the air important for aquatic life?
Ans: Aquatic life depends on dissolved oxygen in water to survive. Fish and other aquatic organisms extract this oxygen through their gills for respiration.

Q16. What is the importance of nitrogen in the atmosphere?
Ans: Nitrogen is an inert gas and helps in diluting the effect of oxygen, making combustion slower and safer. It also plays a key role in the nitrogen cycle, essential for plant growth.

Q17. How does air pressure change with altitude?
Ans: Air pressure decreases with an increase in altitude because the density of air molecules becomes lower as we go higher above the Earth’s surface.

Q18. Why are car tyres inflated more in winter than in summer?
Ans: In winter, air contracts because of the low temperature, causing the tyre pressure to decrease. Thus, more air is added to maintain adequate tyre pressure. In summer, air expands due to higher temperatures, so less air is required to maintain pressure.

Q19. What would happen if there were no atmosphere around Earth?
Ans: Without an atmosphere, there would be no air to breathe, extreme temperature fluctuations, and no protection from harmful solar radiation. Life on Earth would not be possible.

Q20. Describe the role of carbon dioxide in maintaining the Earth’s temperature.
Ans: Carbon dioxide traps heat in the atmosphere, acting as a greenhouse gas, which keeps the Earth warm enough to support life. However, too much carbon dioxide can lead to global warming.

Q21. How does wind help in maintaining the balance of oxygen and carbon dioxide in the atmosphere?
Ans: Wind helps in mixing gases throughout the atmosphere, distributing oxygen and carbon dioxide uniformly. It ensures that plants receive carbon dioxide and animals receive oxygen, maintaining a balance.

Q22. What is the role of water vapour in the atmosphere?
Ans: Water vapour is essential for the water cycle, as it condenses to form clouds and eventually causes precipitation. It also plays a part in regulating temperature by trapping heat.

Q23. Why do we often see dew on grass early in the morning?
Ans: At night, when temperatures drop, the air cools, and water vapour condenses on surfaces like grass, forming tiny droplets of dew.

Q24. Explain why the smell of perfume spreads quickly in a room.
Ans: The smell of perfume spreads due to the movement of air particles, which carry the perfume molecules throughout the room by diffusion.

Q25. How does air resistance affect moving objects?
Ans: Air resistance opposes the motion of objects moving through the air, slowing them down. For example, parachutes slow down a person’s descent by increasing air resistance.

Q26. What happens when you blow air into a balloon?
Ans: When you blow air into a balloon, the air particles inside exert pressure on the walls of the balloon, causing it to expand.

Q27. Why does air temperature differ at various places on Earth?
Ans: Air temperature varies due to differences in latitude, altitude, and proximity to bodies of water, which affect the amount of sunlight an area receives and its heat retention.

Q28. How does the presence of dust particles in the air affect us?
Ans: Dust particles in the air can cause respiratory issues, and allergic reactions, and can also reduce visibility. They play a role in cloud formation by acting as nuclei for water vapour condensation.

Q29. Why do wind speeds increase at higher altitudes?
Ans: At higher altitudes, there are fewer obstacles to slow down the movement of air, and air pressure differences are greater, leading to higher wind speeds.

Q30. Why is there less oxygen in high-altitude regions?
Ans: At higher altitudes, the air is less dense, meaning there are fewer oxygen molecules in a given volume of air, making it harder to breathe.