Q1: What is the atmosphere?
Ans: The atmosphere is the layer of air surrounding the Earth.
Q2: Name the gases present in the air.
Ans: The main gases in the air are nitrogen, oxygen, carbon dioxide, water vapor, argon, and neon.
Q3: Why does a lighted candle covered with a glass tumbler go out?
Ans: The candle goes out because it uses up all the oxygen inside the glass, which is essential for burning.
Q4: What is the most abundant gas in the air, and why can't plants and animals use it directly?
Ans: Nitrogen is the most abundant gas (78%). Plants and animals can't use it directly; they need it converted into nitrates through a process called nitrogen fixation.
Q5: How do plants contribute to maintaining the balance of oxygen and carbon dioxide in the air?
Ans: Plants produce oxygen through photosynthesis, compensating for the carbon dioxide produced by animals and maintaining a balance.
Q1: Explain why there is less air on high mountains and why climbers carry oxygen cylinders.
Ans: At higher altitudes, the air becomes thinner. Climbers carry oxygen cylinders because there's less air, resulting in less oxygen, making it difficult to breathe.
Q2: Describe the process of nitrogen fixation and its importance in the air.
Ans: Nitrogen fixation is the natural process where bacteria convert atmospheric nitrogen into nitrates, which plants use to make proteins. It's crucial because plants and animals can't use nitrogen directly from the air.
Q3: How does respiration contribute to maintaining the balance of oxygen and carbon dioxide in the air?
Ans: Animals breathe in oxygen during respiration and release carbon dioxide. This process is balanced by plants during photosynthesis, where they use carbon dioxide and release oxygen, ensuring a balance in the air.
Q4: Discuss the uses of air, focusing on its role in temperature regulation and protection through the ozone layer.
Ans: Air regulates temperature by spreading the sun's heat and protects life through the ozone layer, which absorbs harmful UV rays.
Q5: Explain the significance of wind as a source of energy and its various applications.
Ans: Wind is a source of energy used in windmills to draw water, grind flour, and generate electricity. It also helps disperse pollen and seeds, and has practical applications like separating husk from grain through winnowing.
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22 videos|80 docs|16 tests
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