Pollution of Water is a chapter in the Class 8 Science textbook of DAV schools. Pollution of water is a major topic of concern. With the rapid pace of industrialization, the water bodies are getting deteriorated with time. This chapter talks about the different causes of pollution and methods to get rid of water pollution. Let us discuss Pollution of Water Solutions one by one.
Pollution of Water Question Answers DAV
A. Fill in the Blanks
1. ___________ is a chemical method of purifying water.
2. ___________ and ___________ constitute agricultural wastes.
3. The presence of domestic sewage, in water, promotes the growth of ___________ and ___________ which use up a lot of oxygen, present in water.
4. Water, that is safe for drinking, is called ___________ water.
Ans A.
1) Chlorination is a chemical method of purifying water.
2) Fertilizers and Pesticides constitute agricultural wastes.
3) The presence of domestic sewage, in water, promotes the growth of algae and bacteria which use up a lot of oxygen, present in water.
4. Water, that is safe for drinking, is called Potable water.
5. One of the purposes of the purification of water is to remove the suspended impurities, present in it.
C. Tick the correct option:
1. Domestic sewage, released into rivers, causes-
Answer: It causes the growth of algae and bacteria.
2. Water, which is safe for drinking, is known as-
Answer: Water safe for drinking can be called Potable water
3. One of the methods, that can help in destroying harmful germs in water, is-
Answer: Chlorination is the method to destroy harmful germs in the water. A lot of people use chlorine tablets in water when the water comes dirty.
4. Suspended particles are made heavier by adding alum. This process is known as-
Answer: Alum can be added to make the suspended particles heavier. This process is called Loading.
5. A method, that can help in conservation of water, is-
Half flush method can be used in conservation of water.
D. Answer the following questions in brief
Question 1: State any two ways that can lead to contamination of water.
1. Bathing of animals in the water bodies
2. Release of industrial waste in nearby water bodies
Question 2: Give the meaning of the term water pollutants.
Anything that deteriorates the clean water bodies and makes it polluted can be called as a water pollutant. It can be anything like the surf released in water by washing clothes on the banks of river.
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Question 3: Name two diseases that can be caused by drinking contaminated water.
Ans 3: The two diseases that can be caused by drinking contaminated water are Typhoid and Jaundice. We should always drink water from a clean source.
Question 4: Name any chemicals that may help in purifying water.
Ans 4: Chlorine and Alum (fitkari) can be used for cleaning water. Chlorine tablets usage is common in areas where water pollution problem is frequent.
Question 5: Name the kind of ‘growths’ in water that lead to a depletion of the oxygen dissolved in it.
Ans 5: Growth of algae and bacteria leads to depletion of oxygen gas dissolved in it.
E. Answer the following questions
1. List the main parameters that need to be followed before water is supplied for drinking purposes.
Ans: These parameter checks are crucial before sending them to houses for drinking purposes.
1. Water should be free from any kind of odour.
Water should not contain any kind of colour in it
The water should be from the growth of algae or bacteria
Water should be sent to water treatment plants before sending them to houses.
Water should not contain metallic impurities dissolved in it as it can cause various diseases.
2. Write, in brief
(i) one physical and
(ii) one chemical method that can be used for ‘water purification’.
Ans (i) Physical method of water purification: Filtration can be used for cleaning some major impurities.
(ii) Chlorination is one of the best methods of water purification. We can add chlorine capsules in the water storage tanks for cleaning the impurities.
4. Suggest some simple steps that can be taken to help in conserving water.
Ans 4: Let us understand some simple steps for the conservation of water.
1. Do not use showers instead make a habit of bathing using a bucket and mug. Showers can waste a lot of water.
2. Do not leave the taps running.
3. Use buckets to water the plants instead of using a spray. It will help in conserving the water.
4. In water scarcity areas, houses should be built in a way such that the rain water gets collected in a tank or storage container.
5. Promote water conservation campaigns in your society and spread the message through social media platforms.
So, these were Pollution Question answers. We have given accurate solutions to DAV Class 8 Science chapter 20 solutions. If you have any queries, feel free to ask through the comments section below. Stay tuned to CareeraAdvice4u and Keep Learning. You can also reach out to us through chat support if you are looking for online or offline coaching for better results.
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