TS 8th Class Biology Study Material 10th Lesson Not For Breathing Not For Drinking

TS Board Telangana SCERT Class 8 Biology Solutions 10th Lesson Not For Breathing Not For Drinking Textbook Questions and Answers.

TS 8th Class Biology 10th Lesson Questions and Answers Telangana – Not For Breathing Not For Drinking

Question 1.
How does air pollution lead to water pollution?
Answer:
The suspended particulate matter (spm) of air pollution leads to water pollution. Due to gravity, slowly the dust particles directly deposit into water bodies, which make the water unsafe for drinking. Sometimes it causes Algal boom.

Question 2.
What steps can be taken up to control air pollution and water pollution?
Answer:
Methods for controlling air pollution:

• In the open cast mining areas and the other mine areas, steps should be taken to decrease the release of pollutants.
• Use of tall chimneys in all factories reduce air pollution.
• Better designed fuel burning equipment should be used in homes and industries, so that fuel is burnt completely.
• Install electrostatic precipitators in the chimneys of industries.
• Reduce vehicular emissions by using non-polluting fuels like CNG.
• Use LPG for domestic use.
• Improve the quality of fuel in automobiles and use catalytic converters in them.
• Make use of renewable alternative source of energy like solar energy, wind energy, and hydro energy.
• The motor vehicles should be maintained properly, so that they comply with pollution norms.
• Use unleaded petrol.
• Plant and grow more and more trees in your surroundings.
• We can protect plants and trees by conducting Vanmahotsav in July every year.

Prevention and controlling of water pollution:

• Toxic industrial wastes should be treated chemically to neutralize the harmful substances present in it before discharging into river water.
• The sewage should not be dumped into the rivers directly. It should be first treated at the sewage treatment plant to remove the organic matter from it in the form of manure.
• The use of excessive fertilizers and pesticides should be avoided.
• The use of synthetic detergents should be minimized (or) biodegradable detergents should be used.
• Dead bodies of human beings and animals should not be thrown into rivers.
• The exacta and other garbage should be treated in a biogas plant.
• Trees and shrubs should be planted along the banks of the rivers.

Question 3.
Why does the increased level of nutrients in the water affect the survival of aquatic organisms?
Answer:
Presence of sewage and fertilizers (Nitrates and phosphates) in polluted water provide a lot of nutrients to the algae present in the water body. As a result excessive growth of algae occurs which is termed as algal bloom. The algae subsequently die and aerobic decomposers become active. They consume rapidly the dissolved oxygen of water to decompose the dead algae. In the absence of dissolved oxygen (high BOD) all the aquatic life in the water body dies. It is known as Eutrophication. It deprives us of one of our sources of food.

Question 4.
Road side plants cannot grow properly – Find your own reasons and explain with your argument.
Answer:

• The dust of the air pollution is deposited on the leaves and it affects the exposure of the leaves to the sunlight, so the photosynthetic rate is affected.
• More harmful gases present in the polluted air makes plants not to grow in some areas.

Question 5.
Sudheer is a traffic constable. What do you think about his health? Give some suggestions to protect his health during duty period.
Answer:

• Sudheer is continuously exposed to air pollution because of his duty as traffic constable.
• Air pollution has a negative impact on human health. So he may get certain diseases like shortness of breath, sore throat,chest pain, nausea, asthma, bronchitis and lung cancer. Extreme effects of air pollution include high BP and cardiovascular problems.

Question 6.
Write a short note on the effects of water pollution in your village. Suggest precautions.
Answer:
In our village,  have seen water in the tanks getting polluted. Open defecation on the banks of tanks, washing clothes, animals and vehicles, bathing, releasing chemical pollutants, falling leaves from nearby trees, garbage are polluting the water.

This pollution is causing harmful effects:

• Human diseases: Pathogens such as viruses, bacteria, protozoans cause various diseases in human beings. Eg : Typhoid, jaundice, dysentery.
• Destruction of useful micro organisms: When untreated industrial wastes get mixed with water in rivers and lakes, they kill the useful micro – organisms present in the water bodies.
• Eutrophication : The process in which excessive growth of algae occurs as a result of extra loading of nutrients in water body.
• Biomagnification of chemicals: Pesticides levels increase in the living organisms at each trophic level of the food chain.

Precautions:

• Open defacation; washing clothes, animals and vehicles to be avoided.
• Bathing In water tanks with unclean bodies to be avoided.
• Factories are to be directed to instal chemical treatment plants before releasing them into water.
• Fallen leaves and other garbage thrown into tanks are be removed frequently.

Question 7.
Visit a pollution check centre. Observe the process of conducting a pollution check and record your findings. You may consider the following areas for your record:
1. Average number of vehicles checked in a certain time period.
2. Time taken to check each vehicle
3. Pollutants checked for
4. The process of testing
5. Permissible limits of emission of various pollutants.
6. Measures taken if the emitted gases are above the permissible limits.
Answer:
Servicing the engine and upgrading the emission standards of the engine to Bharath stage – III.

• 10 vehicles (2/3 wheelers)
• 3-5 minutes.
• Carbonmonoxide and Hydrocarbons
• Automatic machine fitted with computerised testing.
• Levels prescribed in the Motor Vehicle Act 1988 and Central Motor Vehicles Rules 1989.
• Using catalytic converters in the engine.

Question 8.
Organize a field visit to a pond I lake I river present in or near to your village with the help of your teachers.
Answer:
Observations followed by discussion could focus on

• The history of the pond or lake or river.
• Water resources available other than that river! pondl or lake.
• Cultural traditions
• Pollution concerns
• Source of pollution

Question 9.
What is air pollution? Make a flowchart to describe its causes and effects.
Answer:
Addition of air pollutants such as particulate matter, gases and vapours into the atmosphere which have adverse effects on humans is called air pollution.

Question 10.
Clear and transparent water is always suitable for drinking. Comment.
Answer:
The potable water which is suitable for drinking is colourless, without any smell or any unwanted substances.

Question 11.
If our monument like Taj Mahal is effected by air pollution, what is your advice to protect it?
Answer:
Taj Mahal should be protected from air pollutants by taking following precautions.

• Cars and buses are not to be allowed to drive to the Taj Mahal. Only battery run buses or horse – drawn carriages are to be allowed to reach the Taj Mahal.
• Shifting of polluting industries like Mathura oil refinery.
• Using unleaded petrol in the vicinity of the Taj Mahal.
• Switching over to clearer fuels like CNG and LPG.

Question 12.
Reshma is going to talk about controlling measures of soil pollution. Please prepare a write up for her.
Answer:
Following measures can effectively control the soil pollution:

• Making strong embankments along the rivers banks.
• Removal of excess rain water from the fields with out soil erosion.
• Deforestration leads to soil cracks. So afforestation helps to control soil erosion.
• Land should be free from Nuclear power plants and radio active wastes.
• Garbages and various pollutants from the factories should not be mixed in the soil.
• Fly ash and dust from granite and cement industries should not be over thrown.
• Less use of fertilizers and pesticides in agriculture.
• Using of vermi compost, can decrease soil pollution.

Question 13.
To conduct a quiz program on air and water pollution, prepare five thought provoking questions.
Answer:

• What is smog and how it affects human life in metro cities?
• Industrial growth – boon or bane (brings economic development & causes pollution)
• Bringing more no. of automobiles on to the road – indicates – developed nation / polluted country?
• Green revolution – increased food production / soil & water pollution.
• Pharmaceutical companies – bring life saving drugs / cause severe water pollution?

Question 14.
‘Use Bicycle — Avoid motor bikes and cars’.This slogan is prepared by Sravani. Prepare some more slogans on pollution.
Answer:

• Recharge the ground water by throwing the rain water down into the underground aquifiers.
• Recycle, repair and reuse the old things.
• Save electricity. Save natural resources.

Question 15.
If you are a general manager of a chemical industry what precautions you would take to control air and water pollution?
Answer:

• Tall chimneys should be installed to reduce air pollution at the ground level.
• Installing electrostatic precipitators in the chimneys.
• Plant and grow more trees in the surroundings.
• Toxic industrial wastes should be treated chemically to neutralize the harmful substances present in it before discharging into rivers and lakes.

Question 16.
How to minimize the usage of paper In daily life?
Answer:
Measures to minimise the usage of paper:

• Should use both sides of papers.
• Should avoid printing of single line e-mails and unnecessary documents.
• Should use technology such as e-mail, document scanners that can radically reduce paper use.
• Should recycle the paper.

TS 8th Class Biology 10th Lesson Not For Breathing Not For Drinking Intext Questions

Question 1.
When we go on a busy road in the evening a lot of smoke is spread in the surroundings. We get cough and feel uneasy even when we close the nose with napkins.

a. Why do we observe this type of symptoms ? Think about it.
Answer:
Even though we close the nose with napkin, only the suspended particulate matter can be stopped. The air which we breathe is a polluted air and it has more quantum of carbon dioxide, carbon monoxide and sulphur oxide. The supply of oxygen from the lungs through blood is decreased, hence we feel discomfort and get irritation from the throat in the form of cough.

b. if these symptoms will continue, what happens? (Hypothesis)
Answer:

• If the small particulate matter is inhaled continuously it may cause bronchitis, asthma etc.
• The particles of lead oxide present in the automobile exhaust can cause anaemia, brain damage and even death.
• If any particles of mercury are there in the inhaled air, it causes Minimata disease which affects the nervous system.
• The carbon monoxide gas combines with haemoglobin of our blood and forms a stable compound called carboxy haemoglobin. This leads to respiratory problems of suffocation, because haemoglobin will not be available for the supply of oxygen.

Question 2.
Do you find any relation between pH and hardness of water?
Answer:
Hard water is either neutral (pH 7.0) or alkaLine (more than pH 7.0 value) (Soft water is acidic, hard water is alkaline)

Question 3.
Which water sample is colourless?
Answer:
Tap water.

Question 4.
Which water sample is suitable for drinking and why?
Answer:
Tap water, because it is slightly alkaline and very less hardness.

Question 5.
Do you find any change in colour and smell of water in some water samples ? What are your reasons?
Answer:
Water pollution by different pollutants change the colour of river, lake and drainage waters.

Question 6.
Which water sample of your collection is basic in nature?
Answer:
Pond and lake water is more basic.

Question 7.
Are there any visible pollutants In the water sample?
Answer:
Presence:
Pond, water, well water, lake water, and drainage water containis Pathogens / Microorganisms.

It is Poisonous

Ground water is poisonous:

With the pollutants from chemical industries, the ground water has become poisonous. The maximim limit for TDS (Total disposable solids) is 500, but in Choutuppal, Bhudan Pochampalli, Chityal mandais, the tests proved that it is 10000. A borewell water in Dotigudem of Bhudan Pochampalli has 10520 TDS. Koyyalagudem in Choutappal has recorded 9143 TDS. It is 3450 TDS in Choutuppal, 7085 TDS in Aregudem, 2008 TDS in Gundrallapalli are
noted in borewell water. The experts opined that these waters are not useful for drinking or atleast for agricultural purpose. As a result, the crops are dying.

Most dangerous industries are identified as red category industries, dangerous ones come under orange category and less dangerous units come under green category. Bulk drugs, chemicals, oils, textiles, pesticides, steel corne under red category. Rice mills etc come under green category. In the district there are 232 most dangerous industries (Red category), and 16 units under green category. Of these, maximum share is of chemicals and cement industries.

These are concentrated in Bhudan Pochampaffi, Bibi Nagar, Chityal, Nereducherla, Damaracharla, Mattampalli, Tripuraram, Mellachervu, Kodad mandais. Ail these are causing water and air pollution ignoring all rules and emitting more than permitted range. Ban on industries 6 years back. Recognising the severity of Pollution, the pollution control board implemented ban on establishing industries in the district. Knowing this, the industrialists obtained permission before the implementation of ban.

Question 8.
Answer the following questions based on your understanding of the paper clipping.

a. What do you understand after reading the news paper clippings?
Answer:
The ground water of Choutuppal Mandai of Rangareddy district is totally polluted by the discharges of the Red Category Industrial effluents.

b. What are the issues discussed in this news paper clipping?
Answer:

• Maximum permissible total dissolved solids in the ground water is 500, whereas in Choutuppal, Chityal and Pochampally mandais has gone to 10000.
• The industries are categorised into three groups depending on their pollutants. Red, orange and green. Red Category industries are more in number and they cause more pollution when compared to the other in groups.

c. What are its causes and effects?
Answer:
1. Due to the release of untreated pollutants from these industries the ground water is totally polluted and the level of the TDS (total Dissolved Solvents) has reached to 19,520 in Domagudem village of Pochampally mandai, 9,143 in Koyyalaguclem, 3,400 in Mandollagudem 3,531 in Choutuppal mandai. 7,095 in Aragudem, 2,009 in Gundraflapa lii village. (Maximum permissible limit of TDS is 500)

d. How does the problem arise?
Answer:

• In these mandais the Red category industries are more and they are releasing the pollutants with out any treatment. Although the pollution control board has banned the establishment of new factories in this area, the necessary permissions were obtained well before the date of ban
• The industries are not taking any precautions and not planting plants to control pollution.

e) Are you also facing this type of problems in your area? Can you explain reasons behind?
Answer:
Yes, in many areas of my district we are also having the same problem. It occurs because

• The companies like pharmaceuticals, leather industries, paint industries, mini thermal plants, release their pollutants without proper treatment.
• Pollution control board has thorough check on the implementation of methods and machinery to control pollution.

Question 9.
Observations and findings: Record your observation in the following table.
Answer:

TS 8th Class Biology 10th Lesson Not For Breathing Not For Drinking Activities

Activity – 1 : Natural. Disasters – Pollution : 

Collect information from your school Library for the following natural disasters in the world.
1. Volcanic eruptions
2. Forest fires
3. Sand stones
Answer:
1. Volcanic eruptions: Releases various gases and ash into the atmosphere. Japan is having a good number of volcanoes and they erupt now and then causing air and soil pollution.

2. Forest fires: It releases carbon particles (ash) into the atmosphere. Australia, Canada etc., where lot of forest covers are there. They very frequently undergo forest fires.

3. Sand storms: It is common in arid and semi-arid regions. Strong wind blows loose sand and dirt from a dry surface. It is common in desert areas.

Activity – 2: Oil Paper Experiment: 

Take three square pieces of white paper of 5 X 5cm size dipped in oil. Hang these oil dipped paper at three different locations, say, your back yard, your school, near a park, or a parking lot, etc. Let it be there for 30 minutes. Observe and compare all three papers.

a. What did you find on those papers dipped in oil? (Project work)
Answer:
A thin film of oil coating which absorbs the suspended particulate matter (SPM) present in the air.

b. Is there any difference observed for all the three locations? (Project work)
Answer:

• Yes, parking lot has more carbon suspended particles, due to the vehicular emissions.
• Near the park and school the oil papers have lot of dust particles, pollen grains (soil) attached to it due to more dust in the air.
• Very least spm / dust on the paper placed in the backyard of home.

c. Try to find out the answer why this difference occurred? (Project work)
Answer:

• More number of vehicles in the parking lot should not be parked as per the pollution under control specifications.
• The movement of people / crowdy areas are more near the park and school. Vegetation is also less, so soil is uncovered and exposed to erosion.
• The air pollution level at the backyard of home is less.

d. Do you know where the dust particles could have come from? (Pro. work)
Answer:

• From the uncovered soil of the park arid school.
• If any mining area/stone crushers/cement factories are there in near by areas they also cause the air pollution.

e. Name the fuels we burnt in our daily activities including rural and urban areas.
Answer:

• Petrol, diesel, kerosene, LPG, gobargas.
• Fossil fuels and fire wood.

Activity – 3 : Power Generation Plants:

Go to your school library and collect information to make a list of these power generation plants and where they are located.
Answer:
Nuclear power plants in India

• Narora Atomic power station – Narora, UP.
• Rajasthan Atomic power station – Rawatbhata, Rajastan.
• Tarapur Atomic power station – Tarapur, Maharastra
• Kakrapar Atomic power station – Kakrapar, Gujarat.
• Kundankulam Atomic power station – Kundankulum, Tamilnadu.
• Madras Atomic power station – Kalpakkam, Tamilnadu
• Kaiga Nuclear power plant – Kaiga, Karnataka.

Activity – 4: Field visit:

Visit nearby factory, industry (boiled rice mill, brick making kiln, oil mill, food processing mill, etc) present in your area and observe,
Answer:
We visited brick making kiln, it is located 1.5 km away from the school.

a. How are they polluting air and water? (Field experience)
Answer:

• The burning of fossil fuels such as coal is used. Coal is releasing gaseous pollutants like CO₂, CO and sulphur gases.
• The ashes cause soil pollution and gases causes Air pollution.

b. Is there any green belt around the factory? Name the trees they are growing.
Answer:
Yes. Plants like neem, Eucalyptus are seen.

c. Which type of precautions they are taking to prevent pollution?
Answer:
Workers are throwing ashes into open places. They are not taking any precautions.

Activity – 5:

Visit your nearby pond! lake or river and find out the material being discharged in it. Prepare a Biography on it.

a. Ask your teacher about aerobic bacteria and write a note on it with examples.
Answer:
The bacteria which require O₂ for their survival, and which can decompose the organic matter into simple particles in the presence of oxygen are known as AERO BACTERIA. Eg: E – Cou, Staphy locococcus, Heicobecta.

b. Do you know oil slick on sea water? In what way is it dangerous to aquatic life?
Answer:
When the crude oil carrying ships / vessels sank into the oceans due to certain reasons, the oil gets spilled and floats on the water over a radius of 5 – 10 kms. It forms a thin film on the surface of water and does not allow the exchange of gases between air and water. So the aquatic life cannot survive due to the lack of dissolved oxygen. The birds which depend on the aquatic life also die due to the non-availability of food.

TS 8th Class Biology 10th Lesson Not For Breathing Not For Drinking Important Questions

Question 1.
Observe this certificate try to find out answers for the following questions:

a. Which department issues the pollution under control certificate?
Answer:
Transport department, Government of Andhra Pradesh issues. ‘The pollution, under control certificate.

b. For how much time is it valid?
Answer:
It is valid for 6 months.

c. For which type of vehicle has it been issued?
Answer:
Motor vehicles using petrol, desiel, LPG and CNG have to be issued the pollution under control certificate.

d. What is emission test? What components are tested in the pollution check up center?
Answer:
The emissions released by the engine of the vehicles are tested for the levels of Carbon monoxide and Hydrocarbons.

e. What will happen if Carbon monoxide (CO) and Hydrocarbons (HC) readings are higher than the permissible limits reading?
Answer:
The vehicle / engine should be serviced at the authorized servicing station to reduce the emission levels to the standards of Bharat stage – III.

f. Why is there a need of “Pollution Under Control Certificate?”
Answer:
If these emission levels are not tested and the certificate is not obtained, then the quantum of air pollution may increase in our surroundings due to more emission of smoke from vehicles on the roads.

Question 2.
What will happen if harmful organisms or substances enter your body? How do you feel?
Answer:
I may feel a chain reaction of problems right through the rest of the system. These changes can really hurt the health and well being of living organisms.
They causes diseases and affect our metabolism and may lead to very dangerous effects like cancers.

Question 3.
List out the gases that are present in the air.
Answer:
Nitrogen, Oxygen, Argon, Carbon dioxide, Water vapour and other traces.

Question 4.
What are the four major gases in the air?
Answer:

• Nitrogen – 78.084%
• Oxygen – 20.947%
• Argon – 0.934%
• Carbon dioxide – 0.033%

Question 5.
If a person burnt out tyres or dried leaves at a particular place, where shall the smoke and ash goes ?
Answer:
The harmful gases released by the burning of tyres or dried leaves go into atmospheric air. But the winds criss – cross the globe, and carry pollutants to all over the world. This is how areas far way from where the actual pollution is created may be affected, too. So air pollution is not just a local concern, it is a global concern.

Question 6.
Ask your teacher about secondary pollutants why they called so?
Answer:

• The primary pollutants react and produce the secondary pollutants.
• Secondary pollutants are not directly released. eg: Peroxy acetyl nitrate (PAN), Formaldehyde, ozone etc.

These questions are given T.M. Textbook

Question 7.
Kavitha advised her friend Koushik in preparing Ganesh Idol made of clay. Kavitha told him that it is more eco friendly rather than that of idol made of plaster of Paris. How can you support this answer? How do you appreciate her?
Answer:
I support Kavith & pinion.
Plaster of Paris is a chemical substance that pollutes water. Ganesh idol made of plaster of Paris is painted with different chemical colours. When this idol is immersed in water all the chemicals present in the idol mix with water and cause water pollution. Plaster of Paris remains undissolved for a long time in water. All these features damage life of water species. Therefore Ganesh idol should be made of clay which dissolves easily in water.

Appreciation: I appreciate clay Ganesh idol idea of Kavitha. She emphasized the protection of bio diversity.

Question 8.
“Is carbon dioxide pollutant or not ?“ Discuss.
Answer:
If a substance exists in an improper ratio in atmosphere, it is called pollutant.

• The percentage of CO₂ in atmosphere is 0.033%.
• This is an important factor for photosynthesis.
• Man made activities increased the percentage of CO₂ in atmosphere from 0.033% to a great range which caused pollution.
• Excessive presence of CO₂ causes global warming and green house effect.
• Global warming influences melting of ice in polar regions and rise in atmospheric temperature.

Choose the correct answers:

Conceptual Understanding

Question 1.
Which gas plays a major role in global warming? ( )
A) CO
B) Nitrous oxide
C) CO₂
D) Sulphur dioxide
Answer:
C) CO₂

Question 2.
Which of the following is incorrect about effects of acid rain? ( )
i) Acid rain increases the acidity of the soil and water
ii) Acid rain does not affect painted surface of metals
iii) Acid rain is due to the presence of H₂SO₄ and HNO₃ in rain water with a pH of less than 5.
iv) Taj Mahal at Agra is facing threat due to corrosive action of acid rain
A) i & ii
B) i & iii
C) only ii
D) iii & iv
Answer:
C) only ii

Question 3.
Which of the following are not harmful effects of air pollution? ( )
i) Respiratory problems such as allergy, sneezing, bronchitis etc.
ii) Algal blooms
iii) Bio-magnification of heavy metals in food chain
iv) Green house effect
A) i & ii
B) ii & ii
C) iii & iv
D) i & iv
Answer:
B) ii & ii

Question 4.
Air is a mixture of ( )
A) Nitrogen, oxygen, methane, carbon dioxide
B) Nitrogen, carbon dioxide, oxygen, carbon monoxide, water vapour
C) Nitrogen, oxygen, carbon monoxide, water vapour
D) Nitrogen, oxygen, carbon dioxide, water vapour
Answer:
D) Nitrogen, oxygen, carbon dioxide, water vapour

Question 5.
Which of the following is also called marsh gas? ( )
A) Methane
B) Carbon dioxide
C) CFC
D) Sulphur dioxide
Answer:
A) Methane

Question 6.
The two forms of oxygen found in the atmosphere ( )
A) Water and ozone
B) Water and oxygen
C) Ozone and oxygen
D) Water and CO₂
Answer:
C) Ozone and oxygen

Question 7.
One of the following processes is not a step involved in the water cycle operating in nature: ( )
A) Evaporation
B) Transpiration
C) Precipitation
D) Photosynthesis
Answer:
D) Photosynthesis

Question 8.
Which of the following statements does not give the correct definition of water pollution? ( )
A) The addition of undesirable substances to water bodies.
B) The removal of desirable substances from water bodies.
C) A change in pressure of the water bodies.
D) A change in temperature of the water bodies.
Answer:
C) A change in pressure of the water bodies.

Question 9.
The major gaseous substance in the air ( )
A) 72%-N₂
B) 78%-N₂
C) 76%.N₂
D) 75%-N₂
Answer:
B) 78%-N₂

Question 10.
The % of CO₂ in the atmosphere: ( )
A) 0.1
B) 0.2
C) 0.033
D) 0.939
Answer:
C) 0.033

Question 11.
The fuel that reduces pollution ( )
A) Petrol
B) Coal
C) C.N.G
D) Diesel
Answer:
C) C.N.G

Question 12.
Find out the odd one: ( )
A) volcanic eruptions
B) forest fire
C) sand storms
D) deforestation
Answer:
D) deforestation

Question 13.
Air pollution causes ( )
i) Ozone depletion
ii) Green house effect
iii) Global warming
iv) Acid rain
A) i, ii, iii
B) i, ii
C) i, ii, iv
D) All
Answer:
D) All

Question 14.
Pollution check certificate is issued by ( )
A) pollution control board
B) forest department
C) traffic police
D) vehicle manufacturers
Answer:
A) pollution control board

Question 15.
Chernobyl disaster happened in which country? ( )
A) USA
B) Australia
C) Japan
D) Russia
Answer:
D) Russia

II. Asking Questions and Making Hypothesis

Question 16.
What would happen if all the oxygen present in the environment is converted into ozone? ( )
A) We will be more protected
B) It will become poisonous and kill living beings.
C) Ozone is not stable, hence it will be toxic
D) It will help harmful sun radiations to reach earth and damage many life forms.
Answer:
B) It will become poisonous and kill living beings.

Question 17.
If the temperature of water increases, the availability of oxygen ( )
A) decreases
B) increases
C) equals
D) all
Answer:
A) decreases

III. Experiments and Field Investigation

Question 18.
You did oil paper experiment in your school. Find the materials you used for that ( )
i) 5 x 5cm white paper
ii) Oil
iii) Thread for hanging
A) i
B) ii
C) iii
D) All
Answer:
D) All

Question 19.
What are the materials used to collect water samples for pH testing ( )
A) Glass tumblers
B) Litmus paper
C) Soap
D) All
Answer:
D) All

IV.  Information Skills and Projects

Question 20.
Observe the following table. This can be used for the observation of ………….. ( )

A) soil pollutants
B) water pollutants
C) sound pollutants
D) air pollutants
Answer:
B) water pollutants

VI. Appreciation and Aesthetic Sense, Values

Question 21.
Find which of the following are used to reduce air pollution ( )
i) install tall chimneys
ii) better designed fuel burning equipments
iii) install electrostatic precipitators
A) i
B) ii
C) iii
D) all
Answer:
D) all

Question 22.
Find the incorrect source for suspended particulate matter ( )
A) Power plants
B) Quaries
C) Air coolers
D) Cement factory
Answer:
C) Air coolers