A. Answer the following questions in short:
1. What are the different ways in which water gets contaminated?
2. At an individual level, how can you help reduce air pollution?
3. Clear, transparent water is always fit for drinking. Comment.
4. You are a member of the muncipal body of your town. Make a list of measures that would help your town to ensure the supply of clean water to all its residents.
5. Explain the differences between pure air and polluted air.
6. Explain circumstances leading to acid rain. How does acid rain affect us?
7. Describe the ‘Greenhouse Effect’ in your own words.
8. Prepare a brief speech on global warming. You have to deliver the speech in your class.
9. Describe the threat to the beauty of the Taj Mahal.
10. Why does the increased level of nutrients in the water affect the survival of aquatic organisms?
11. How can we reduce, reuse and recycle water?
12. A lot of dry leaves are collected in a school garden and are burnt everyday. Do you think that it is right to do so? If not, what should be done to dispose off the dry leaves?
B. Tick (✓) the correct option:
1. Which of the following is not a greenhouse gas?
(a) Carbon dioxide
(b) Sulphur dioxide
(c) Methane
(d) Nitrogen
2. The exhaust from CNG vehicles contains too much of:
(a) SPM
(b) sulphur dioxide
(c) carbon monoxide
(d) none of these
3. Of the total water on earth, freshwater is:
(a) 97.4%
(b) 2.6%
(c) 2.0%
(d) 0.01%
4. Fertilisers and pesticides are the main cause of:
(a) water pollution
(b) soil pollution
(c) air pollution
(d) food poisoning
5. Air pollution can be prevented by:
(a) burning fuels like wood and coal
(b) deforestation
(c) using biogas and solar energy as fuels
(d) volcanic eruption
C. Fill in the blanks:
1. Algae can be used to produce oxygen by the …………………. process.
2. Suspended particles of dust, smoke and sand are called ……………….. .
3. Two examples of greenhouse gases are …………………. and …………….. .
4. …………………. or ………………… can be used to kill the disease causing microorganisms present in water.
D. State True or False:
1. There are no alternatives for fossil fuels. ………………
2. Water pollution is caused by the waste water given out by the factories. ………………..
3. Waste water from agricultural land do not cause water pollution. ……………………
4. CNG contains sulphur which forms sulphur dioxide upon burning. …………………
5. Clean fuels like natural gas do not contribute to the greenhouse gases. …………………..
E. Match the following:
| ‘A’ | ‘B’ |
| 1. Water pollution | a. CO2 |
| 2. Air pollution | b. CFCs |
| 3. Global warming | c. Acid rain |
| 4. Ozone layer depletion | d. Fertiliers, pesticides |
| 5. Corrosion of statues, buildings | e. Oxides of nitrogen and sulphur |
F. Find out with the help of your teachers and the internet (if possible), whether there are any international agreements to control global warming. Which are the gases covered under these agreements?
G. Write one cause and harmful effects of following pollutants:
