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GURUKUL CENTRAL ACADMY, CH- 15- water, WORKSHEET-1, A. Refer to the textbook, B. 1. b, 2. a 3. d. 4.e 5. c, C. D. E. Refer text book, WORKSHEET-2, A. The steam from the cooked rice condenses on the cool surface of the, lid to form water droplets., B. C. D. Refer text book, , EXERCISES, A., , 1. d. 2. c. 3. a. 4. d. 5. a. 6. b. 7. c., , B., , 1. True 2. True 3. True 4. False 5. False, , C., , 1. solid, liquid, gas, 2. transport, 3. temperature, 4. cannot, 5. salts, impurities, , D., , 1. d. 2. c. 3. b. 4. e. 5. a., , E., , 1. Humidity 2. Freezing 3. Epidemic 4. Flood 5. Sea, , F., , 1. 70 per cent

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GURUKUL CENTRAL ACADMY, 2. The level of groundwater at a place is called the water table., 3. 3%, 4. Plants release excess water in the form of water vapour through, stomata present in the leaves by a process called transpiration., 5. Rain, G., , 1. Water oozes out from our skin as sweat. The sweat dries out taking, away a lot of heat. This helps in cooling down our body. Thus,, water regulates our body temperature and keeps us cool., 2., , 3., , Water is converted into water vapour by boiling. Transpiration and, evaporation., • We need water to drink. Our body cannot perform, its functions if water is deficient in our body. Water, is also essential for cooking, bathing, washing and cleaning., • Water is used in agriculture. Different crops need different, amount of water. Sometimes when the rainfall is not enough, the, fields need to be irrigated., • Water forms the natural habitat of many animals such as fish,, dolphins, whales as well as plants such as lotus, chestnut and, hydrilla., • Water can dissolve more substances than any other liquid., Therefore it is called a universal solvent., , 4., , The water vapour present in the air condenses on dust and smoke, particles to form tiny droplets of water. These droplets of water, stick together to form clouds., , 5., , Because it is cooler above in the atmosphere.

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GURUKUL CENTRAL ACADMY, 6., , H. 1., , The water table of the place goes down and the wells and tube, wells dry up. There is shortage of drinking water. Plant and animal, life is affected badly. The land becomes infertile and there is loss, of vegetation. Crops are affected and there is shortage of food and, fodder. Aquatic plants and animals die. Animals die due to, shortage of water., Refer text on page no. 166., , 2., , Water changes its states and continuously moves from the earth, to the atmosphere and from the atmosphere back to the earth, again. This continuous circulation of water in nature is called, water cycle., Refer diagram 15.6 from page 165., , 3., , Due to the increasing population, the usage of water is increasing, day by day. We are not economical in using water. As a result of, this, the water table is going down in the cities., , 4., , We should not waste water but conserve it. Using water, judiciously, maintaining its quality, developing water resources, and preventing its pollution are some of the ways to conserve, water. Some of the other ways to save and conserve water which, you can follow are listed below., • Get faucets, pipes, toilet cisterns checked at home for leaks., • Take shorter showers or use a bucket while bathing. Turn off the, taps intermittently while rinsing clothes, utensils or while you, brush your teeth. Encourage people at home to run the washing, machines full load., • Plant more trees in your surroundings. This leads to, increase in the water table.

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GURUKUL CENTRAL ACADMY, 5., , 6., , Collection of rainwater from surfaces on which rain falls and, storing it for future use is called rainwater harvesting. Rainwater, can be harvested in following ways:, • Collecting rainwater from the rooftops of buildings in the filter, tank containing sand and pebbles for future use is called rooftop, rainwater harvesting. The water from, the filter tank is then made to seep into another tank for storage., This water can be used later for gardening, bathing, cleaning,, washing floor, etc., • The sides of the road should have brick lining so that rainwater, can seep down and increase the level of groundwater., • The domestic sewage and the industrial wastes are collected, through drains which go into the rivers and contaminate the water., • Use of large amounts of insecticides, pesticides or fertilisers by, farmers in their farms that are washed away by rainwater into, nearby rivers., • Littering on the land or in water is an additional source, of water pollution.