Page 116 - ICSE Chemistry 6

SHORT AND PRECISE
A. Show the given text in the form of fl owcharts.

1. Components of air and their uses
2. Fuels and their uses
3. Causes and eff ects of air pollu on

B. Give reasons for the following statements.
1. The composi on of air is not constant everywhere.
2. Air is a mixture and not a compound.
3. Carbon dioxide is essen al for photosynthesis.
4. Traffi c policemen regula ng traffi c at the traffi c signal wear a mask.
5. Burning of coal results in air pollu on.

6. Photosynthesis occurs only during the day me.
7. Respira on and photosynthesis are two opposing processes.
8. Plan ng more and more trees is the best solu on to air pollu on.

C. Answer in short.
1. What is atmosphere?
2. What is the composi on of air?
3. What is nitrogen fi xa on?
4. Carbon dioxide is crucial for sustaining life. Comment

5. What is the role of dust par cles in the forma on of clouds?
6. What is respira on?
7. What are air pollutants? Name some of the main air pollutants.
8. Why do you understand by deple on of ozone layer?

AT LENGTH

A. Diff eren ate between the following.
1. Respira on and combus on 2. Photosynthesis and respira on
3. Air pollutants and greenhouse gases 4. Greenhouse eff ect and global warming
B. Read the given experiment to show that the soil contains trapped air. Iden fy the incorrect parts
of the process.
To show that soil contains trapped air which is used by the organisms living in soil and by the roots of
plants to respire
• Take some lime water in a beaker.
• Add a handful of salt and sand in the beaker.
• Small bubbles of carbon dioxide are formed.
• This shows that air is present in the soil par cles.
• The organisms living in the soil and the roots of plants use the air trapped in the soil.

C. Answer in detail.
1. What are the uses of nitrogen?

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