I. One Word Answer type Questions
1. Name two processes that consume oxygen in air.
2. Name one process which puts back oxygen in air.
3. Name one process which removes carbon dioxide from air.
4. Name a gas in air which is used by plants for making food by photosynthesis.
5. Name two processes which put back carbon dioxide into air.
II. Short Answer Type Questions
6. Atmosphere is a blessing. Justify your answer.
7. Write the main causes of air pollution.
8. What is air pollution? State some steps to control air pollution.
III. Long answer Type Questions
9. How will you show that air (or oxygen) is necessary for burning?
10. Explain how, the oxygen in air (or atmosphere) is replaced.
Answers
Answer:
1. Two examples of processes that use oxygen are: Cellular respiration, wherein oxygen and glucose are consumed, producing carbon dioxide and water in...
2. 1. Plants - Plants create the majority of the oxygen we breathe through a process called photosynthesis. In this process plants use carbon dioxide, sunlight, and water to create energy. In the process they also create oxygen which they release into the air.
3. Photosynthesis
Photosynthesis removes carbon dioxide naturally — and trees are especially good at storing carbon removed from the atmosphere by photosynthesis.
4. To perform photosynthesis, plants need three things: carbon dioxide, water, and sunlight. for photosynthesis. Carbon dioxide enters through tiny holes in a plant's leaves, flowers, branches, stems, and roots. Plants also require water to make their food.
5. Carbon dioxide is added to the atmosphere naturally when organisms respire or decompose (decay), carbonate rocks are weathered, forest fires occur, and volcanoes erupt. Carbon dioxide is also added to the atmosphere through human activities, such as the burning of fossil fuels and forests and the production of cement.
6. Answer. The atmosphere absorbs the energy from the sun, recycles water and other chemicals, and works with the electrical and magnetic forces to provide a moderate climate. The atmosphere also protects us from high-energy radiation and the frigid vacuum(cold) of space.
7. Air pollution is caused by solid and liquid particles and certain gases that are suspended in the air. These particles and gases can come from car and truck exhaust, factories, dust, pollen, mold spores, volcanoes and wildfires.
8. Reduce the number of trips you take in your car. Reduce or eliminate fireplace and wood stove use. Avoid burning leaves, trash, and other materials. Avoid using gas-powered lawn and garden equipment.
9. After some time, when all the oxygen of air inside the gas jar is used up, then the burning candle gets extinguished. This proves that air is necessary for combustion of substances.
10. Oxygen is replaced in the atmosphere by the plants as they prepare food (photosynthesis). Carbon dioxide is replaced by the animals for the plants to consume.