GSEB Class 6 Science Solutions Chapter 15 Air Around Us

Question 1. What is the composition of air?
Answer: Air is a blend of nitrogen, oxygen, carbon dioxide, water vapor, and several other gases. A few small dust particles might also be found in it.
In simple words: Air is made of gases like nitrogen, oxygen, and carbon dioxide, plus water vapor and some dust.

Exam Tip: Remember the main components of air (nitrogen, oxygen, carbon dioxide, water vapor) and mention dust particles for a complete answer.

Question 2. Which gas in the atmosphere is essential for respiration?
Answer: Oxygen.
In simple words: Oxygen is the gas needed for breathing.

Exam Tip: Directly state "Oxygen" as the key gas for respiration. Avoid adding extra details unless specifically asked.

Question 3. How will you show that air supports burning?
Answer: Take two lighted candles of similar size and place them on a table. Put a glass jar over one of the burning candles. After a few minutes, the covered candle goes out. Since the air supply is blocked by the glass jar, the candle's flame stops. Meanwhile, the uncovered candle keeps burning. This test shows that air helps things burn.
In simple words: Cover a burning candle with a glass jar; it will go out because it runs out of air, while an uncovered candle keeps burning. This shows air helps fire.

Exam Tip: Clearly describe the setup with two candles (one covered, one uncovered) and explain the role of air supply in the experiment's outcome.

Question 4. How will you show that air is dissolved in water?
Answer: Place some water in a glass container or a beaker. Warm it gently on a tripod stand. Before the liquid starts to boil, observe the inside surface of the container closely. You will notice small bubbles forming inside. As it heats, the air already mixed in the water comes out as these bubbles.
In simple words: When you slowly heat water in a pot, tiny bubbles form inside before it boils. These bubbles are air leaving the water.

Exam Tip: Focus on the observation of bubbles forming on the inner surface of the vessel before boiling, which indicates dissolved air escaping.

Question 5. Why does a lump of cotton wool shrink in water?
Answer: A piece of cotton wool contains air within the spaces between its fibers. When water fills these spaces, it replaces the trapped air. As a result, the cotton mass gets heavier and also becomes smaller because the air pockets are gone.
In simple words: Cotton wool shrinks in water because water takes the place of the air trapped inside its fibers, making it smaller and heavier.

Exam Tip: The key idea is that water displaces the air present in the gaps of the cotton fibers, leading to shrinkage and increased weight.

Question 6. The layer of air around the earth is known as _____.
Answer: Atmosphere.
In simple words: The blanket of air around our planet is called the atmosphere.

Exam Tip: Use the precise scientific term "Atmosphere" for the layer of air surrounding the Earth.

Question 7. The component of air used by green plants to make their food, is _____.
Answer: Carbon dioxide.
In simple words: Green plants use carbon dioxide from the air to make their food.

Exam Tip: Remember that carbon dioxide is the essential gas for photosynthesis in green plants.

Question 8. List five activities that are possible due to presence of air.
Answer: The things we can do because air is present include:
(a) Creating a basic pinwheel
(b) Building a weather vane
(c) Breathing to stay alive
(d) Allowing materials to burn
(e) The process of photosynthesis.
In simple words: Air lets us fly kites, use windmills, breathe, helps things burn, and allows plants to make food.

Exam Tip: When listing activities, choose a variety of examples that demonstrate different properties or uses of air (e.g., movement, survival, combustion, biological processes).

Question 9. How do plants and animals help each other in exchange of gases in the atmosphere?
Answer: The proper amount of oxygen and carbon dioxide in the air is kept stable. This happens because of breathing in both plants and animals, and also through the process of photosynthesis in plants.
In simple words: Plants give out oxygen that animals breathe, and animals give out carbon dioxide that plants use. This keeps the air balanced.

Exam Tip: Explain the interdependent roles of respiration (by both plants and animals) and photosynthesis (by plants) in maintaining the balance of oxygen and carbon dioxide in the atmosphere.