Important Questions for Class 6 Science - Air around Us

Very Short Answer Type Questions

Q1: What is the thin blanket of air surrounding the Earth's surface called?
Ans: The thin blanket of air surrounding the Earth's surface is called the atmosphere.

Q2: What is the main constituent of air that helps in the process of respiration?
Ans: The main constituent of air that helps in the process of respiration is oxygen.

Q3: What is the percentage of oxygen in dry air?
Ans: Dry air contains about 21% of oxygen.

Q4: What is the primary function of water vapor in the air?
Ans: The primary function of water vapor in the air is to maintain the water cycle.

Q5: What happens to the air when it comes in contact with cold surfaces?
Ans: When air comes in contact with cold surfaces, water vapor in the air condenses into droplets of water.

Q6: What is the percentage of nitrogen in dry air?
Ans: Dry air contains about 78% of nitrogen.

Q7: Which gas is produced as a byproduct of respiration and burning?
Ans: Carbon dioxide is produced as a byproduct of respiration and burning.

Q8: What is the main component of smoke released by burning?
Ans: The main component of smoke released by burning is fine dust particles.

Q9: What do bubbles in boiling water indicate?
Ans: Bubbles in boiling water indicate the presence of air molecules escaping from the water.

Q10: How do animals living underwater obtain air for respiration?
Ans: Animals living underwater obtain air for respiration from the air dissolved in water.

Short Answer Type Questions

Q11: Explain the role of oxygen in the process of respiration and combustion.
Ans: Oxygen is essential for the process of respiration in humans, animals, and combustion (burning). It is required for the release of energy from food during respiration and is necessary for fires to burn.

Q12: Discuss the significance of maintaining the balance of oxygen in the atmosphere.
Ans: Maintaining the balance of oxygen in the atmosphere is crucial for the survival of humans, animals, and plants. Plants produce oxygen through photosynthesis, which is essential for breathing, while animals and humans consume oxygen during respiration.

Q13: Why is it advised to breathe through the nose rather than the mouth in dusty environments?
Ans: Breathing through the nose is advised in dusty environments because the fine hairs and mucus in the nose filter out dust particles, preventing them from entering the respiratory system and causing harm.

Q14: Explain how air bubbles in heated water and soil prove the presence of air molecules.
Ans: Air bubbles in heated water and soil indicate the presence of air molecules in these substances. When heated, air dissolved in water escapes as bubbles, and adding water to soil displaces air molecules, both of which confirm the existence of air.

Q15: How do windmills utilize the movement of air, and what are their various applications?
Ans: Windmills utilize the movement of air (wind) to rotate their blades, which can be used to draw water from wells, run flour mills, generate electricity, and more.

Long Answer Type Questions

Q16: Explain the importance of air in various aspects of life and technology, giving examples of its applications.
Ans: Air has multiple uses, such as facilitating wind energy generation, enabling flight for birds and insects, and playing a role in the water cycle. It is essential for combustion, respiration, and transportation.

Q17: Discuss the significance of the water cycle in maintaining life on Earth.
Ans: The water cycle, driven by the presence of water vapor in the air, is vital for sustaining life on Earth. It ensures the availability of freshwater, supports ecosystems, and helps regulate global temperatures.

Q18: Explain how the balance of oxygen in the environment is maintained through the processes of photosynthesis and respiration.
Ans: The balance of oxygen in the environment is maintained as plants produce oxygen through photosynthesis, while animals and humans consume it during respiration. This continuous cycle sustains the required levels of oxygen in the atmosphere.

Q19: Describe the role of air in enabling various forms of transportation, including flight, sailing, and wind energy.
Ans: Air plays a crucial role in transportation by enabling flight for birds and aircraft, sailing for boats and yachts, and wind energy generation using windmills. Its properties are essential for these modes of transportation.

Q20: Explain how air pollution is caused and its adverse effects on the environment and human health.
Ans: Air pollution is caused by the release of harmful gases, smoke, and fine dust particles into the air. It can lead to respiratory problems, environmental degradation, and climate change. Effective measures are needed to reduce air pollution and protect human health and the environment.