NCERT Solutions Class 4 Environmental Studies Chapter 18 Too Much Water Too Little Water

Discuss (Page 147)

Q.1. How can dirty water harm our body?

Ans. Dirty water can cause many diseases.

Q.2. Have you ever got dirty water in your area? What was the reason for this?

Ans. Yes. It was due to leakage in the pipe.

Q.3. Has anyone you know fallen sick because of dirty water? Talk about this.

Ans. Yes. My friend got dysentery.

Q.4. When the guest came to Suguna’s house, they offered him a cold drink, because they thought he should not drink the water. What do you think suguna’s family must be doing for their drinking water?

Ans. They must make the water fit for drinking. They can add alum and chlorine tablet for this purpose.

Q.5. The guest said he did not take cold drinks. Why do you think he said this?

Ans. Cold drinks are aerated and can cause trouble in our body mainly in digestive system.

Read and Write (Page 148)

Q.1. Have you ever had a shortage of water in your house? When?

Ans. Yes. It a week during last summer.

Q.2. What did you have to do then?

Ans. We had to collect water from the water tankers.

Page 149

Q.1. Have you ever played in water? Where? When?

Ans. Yes. In the water fun village last month.

Q.2. Are there times when you are not allowed to play in water? What are the reasons for this?

Ans. (1) There is shortage of water.

(2) The water is deep.

(3) The water is dirty.

Q.3. If you go to a Water Park, find out from where the water comes to the park.

Ans. It comes from the pipeline.

Write in your notebook (Page 150)

Q.1. Why was Raziya worried when she read the news in the paper?

Ans. She read that gutter water had mixed in the water pipe. This makes the water dirty.

Q.2. Raziya asked that all the water that was filled in the day before should be thrown. Could this water have been used for something else? What kind of things?

Ans. This water could be used for washing, watering plants in the garden, etc.

Q.3. In what way did she plan to make the water clean?

Ans. By boiling.

Q.4. Do you know of any ways to make water clean? Describe them.

Ans. By adding alum, filtering, chlorine tablet, etc.

Q.5. Suppose Raziya had not read the newspaper, and everyone had drunk the water without boiling it, what could have happened.

Ans. They would fall sick.

Discuss (Page 150)

Q.1. Where Deepak lives, everyone has to stand in a line to fill water form the common tap. In Raziya’s house, water comes all day in the tap. Why is this?

Ans. Raziya’s locality has got the facility of house connection.

Q.2. Raziya read news about the water in the newspaper. Have you read any news about water in the newspapers? What kind of news?

Ans. Yes. Once I read that water in Bengal contains arsenic.

Water Survey in School (Page 151)

Q.1. Look and Note:

Put a (Tick) in right box.

(i) Where does the water in your school come form?

Ans. Tap(tick)Tank(tick) Hand pump(tick)

(ii) In your school, from where do you take water to drink?

Ans. Tap(tick)Tank ( ) Hand pump( )

Q.2. If there is no tap, matka or hand pump, then how do your get drinking water?

Ans. From the water board’s supply tankers.

Q.3. Is there water in all the taps/hand pumps?

Ans. No.

Q.4. Is there any tap which is leaking or dripping?

Ans. No.

Q.5. Are all the matkas filled with water, and are they covered?

Ans. No. But the matkas are covered.

Q.6. Are the matkas and other water containers get cleaned regularly?

Ans. Yes.

Q.7. How is water made safe for drinking?

Ans. First alum is added and then chlorine tablet is dropped.

Q.8. Is there a long handled ladie to take water form the matka or container? How many ladies are there?

Ans. Yes. One ladles for each matka.

Q.9. Is the place around the drinking water taps or container and matkas clean regularly?

Ans. Yes.

Think and Discuss (Page 153)

Q.1. Why do the drinking water places get dirty?

Ans. Due to various human activities like by washing, etc.

Q.2. What can we do to keep these places clean?

Ans. Do not wash near the place, etc.

Find out and write in your notebook (Page 153)

Q.1. How often (once a day, once in two days, etc.) are the containers, matkas and ladles cleaned? Who clans them?

Ans. Once in two days. Peon clans them.

Q.2. How many children are there in your school? How many drinking water taps, matkas or hand pumps are there?

Ans. There are about two hundred children. There are five drinking water taps.

Q.3. Who cleans the places near the water?

Ans. Peon.

Q.4. Where does the water that is spilt go?

Ans.To the school garden through drain pipes.

Group 2 (Page 153)

Q.1. What are the toilet arrangements in you school?

Ans. Built toilet (Tick) Open area ( )

Q.2. How many toilets are there?

Ans. 6

Page 154

Q.1. Put (Tick) in the box and write wherever it is required …….

i. Are there separate toilet for girls and boys? (Tick)Yes ( ) No

ii. Is there water in the toilets?(Tick)Yes ( ) No

iii.From where does the water come?

From tap(Tick)Yes ( ) No

From filled containers ( )Yes ( Tick) No

Has to be brought( )Yes ( Tick) No

iv.Is there water for washing hands near the toilet? (Tick)Yes ( ) No

v. Do you wash your hands after using the toilet?(Tick)Yes ( ) No

vi.Is there any tap that is leaking or dripping( )Yes ( Tick) No

vii. Are the toilet places kept clean? (Tick)Yes ( ) No

Find out and Write (Page 155)

Q.1. How many boys and how many girls are there in your school?

Ans. Boys (1000) Girls (900)

Q.2. How many toilets are there for girls, and how many for boys?

Ans. Boys (4) Girls (4)

Q.3. If there are not taps, who brings the water for the toilet? From where does the water have to be brought?

Ans. The student himself from the hand pump.

Q.4. Who keeps the place clean?

Ans. Peon.

Talk about (Page 155)

Q.1. What can be done to keep the toilets clean?

Ans. Regular washing.

Q.2. What can each of us do for this?

Ans. Maintain cleanliness.

Q.3. Have you seen a toilet at a bus stand or railway station? How are they different from the toilet at home?

Ans. Toilet at bus stand are dirty.

Question. Ramu had a peppermint in his mouth for some time. Even though he did not bite into the peppermint, he noticed that it got smaller and finally disappeared. What happened to the peppermint?
(a) The peppermint disappeared because of the heat.
(b) Ramu chewed the peppermint and ate it up.
(c) The peppermint dissolved in Ramu's mouth bit by bit.
(d) Ramu swallowed the peppermint. Therefore it disappeared.

Answer : C

Question. Here is some information on whether oil paint dissolves in different substances or not. A painter used oil paint to paint the walls of a house. Which of these substances will help him clean the brush?

(a) Kerosene
(b) Hot water
(c) Spirit
(d) Cold water

Answer : A

Question. Which item has been put under the WRONG HEADING in the table below?

(a) Piece of wood
(b) Eraser
(c) Lemon Juice
(d) Candle

Answer : B

Question. Which of the following properties of water will change when it is poured from one vessel to another?
(a) Shape of water
(b) Colour of water
(c) Amount of water
(d) Smell of water

Answer : A

Question. Certain substances like salt and sugar dissolve in water. That means that when they are mixed in water, they disappear and we get a clear solution. Here is some information about some other substances. Use this information to answer questions  6 and 7.

(a) All liquids dissolve in water.
(b) Some solids dissolve in water.
(c) White things dissolve in water.
(d) Wax dissolves in water.

Answer : A

Question. Certain substances like salt and sugar dissolve in water. That means that when they are mixed in water, they disappear and we get a clear solution. Here is some information about some other substances. Use this information to answer questions 6 and 7.Which of these substances will give a clear solution when mixed with water?

(a) Cooking oil and lemon juice.
(b) Glucose and lemon juice.
(c) Saw dust and camphor.
(d) Glucose and cooking oil.

Answer : B

Question. What must have happened to the glass of water in the first picture in the 10 minutes before it reached the state in the second?

(a) The glass was placed in a refrigerator.
(b) The glass was heated on a stove.
(c) Ice cubes were added to the water.
(d) The glass was left untouched.

Answer : B

Question. Azim thought of a man-made object that gave light and does not use electricity. What was the object that Azim thought of?

(a) Sun
(b) Candle
(c) Bulb
(d) Wood

Answer : B

Question. At a funfair, Sehwag noticed the various balloons shown above. Based on his observation, Sehwag can conclude that_________.

(a) all gases have weight
(b) gases form when liquids are heated
(c) gases take the shape of their containers
(d) None of the above

Answer : C

Question. Which of these was invented first?
(a) Telegraph
(b) Telephone
(c) Radio
(d) Television

Answer : A

Question. Which of these will DEFINITELY float on water?
(a) A pencil box
(b) An ice cube
(c) A tree trunk
(d) A knife

Answer : B

Question. If the SAME amount of orange juice is poured into three empty glasses, which picture correctly shows the level of juice in the glasses?

Answer : A

Question. Salim wanted to understand how much milk his pet cat drinks in one day. Which of these can help him measure that?

Answer : B

Question. A doctor asks Sadhana to measure and note the amount of water she drinks every day. Which of the following instruments could she use for the purpose?

Answer : D

Question. Asmita takes a glass of water, adds a spoon of tea leaves and another spoon of sugar and stirs the mixture well. She passes this mixture through a kitchen sieve (filter). What will remain on the sieve?

(a) water only
(b) sugar only
(c) tea leaves only
(d) sugar and tea leaves

Answer : C

Question. Roy has gone to a doctor. What is the doctor doing?

(a) measuring his temperature
(b) measuring his blood pressure
(c) giving him a medicine
(d) tying him a bandage 

Answer : B

Question. Ramesh has taken equal quantities of water in 4 identical glasses. In the first glass, he added a spoon of salt. In the second glass he added a spoon of sugar. In the third glass he added a spoon of orange squash. And in the fourth glass he has added a spoonful of small pebbles. In which of the glasses will the water level rise the most?
(a) First glass
(b) Second glass
(c) Third glass
(d) Fourth glass

Answer : D

Question. Water evaporates from rivers and seas to form clouds which give us rain. Sea water is salty, but rain water is not - where does the salt go?
(a) It remains in the sea.
(b) It remains in the air.
(c) It remains in the cloud.
(d) It changes into water vapour.

Answer : A

Question. At a funfair (mela), Dravid observed the various containers with liquids as shown above. Based on this, Dravid can conclude that

(a) liquids are colourless and do not have any smell
(b) all liquids can be cooled to form solids
(c) liquids take the shape of their container
(d) all liquids have weight

Answer : C

Question. What must have happened to the glass of water in the first picture in the 10 minutes before it reached the state in the second?

(a) The glass was placed in a refrigerator.
(b) The glass was heated on a stove.
(c) Ice cubes were added to the water.
(d) The glass was left untouched.

Answer : B

Question. Some solids directly change state and become gases without first becoming liquids. This is called sublimation. Which of these is an example of sublimation?
(a) A bottle of perfume is opened in the corner of a room.
(b) If an ice-cube is left in the hot sun, nothing remains after an hour.
(c) When water is boiled, it changes to steam.
(d) Moth balls used to keep insects away disappear in a few days.

Answer : D

Question. The picture here shows the water-cycle. What is the main difference between the water in P and Q?

(a) P - Water is in liquid form; Q - Water is in vapour form.
(b) P - Water is in vapour form; Q - Water is in liquid form.
(c) P - Water is salty to taste; Q - Water is not salty to taste.
(d) P - Water is not salty to taste; Q - Water is salty to taste.

Answer : D

Question. Which of these has been put under the wrong heading above?

(a) Orange juice
(b) candle
(c) water
(d) Ice cube

Answer : D

Question. Which is the group in which all the items sink in water?

Answer : B

Question. Which of these substances will give a clear solution when mixed with water?
(a) Cooking oil and lemon juice.
(b) Glucose and lemon juice.
(c) Saw dust and camphor.
(d) Glucose and cooking oil.

Answer : B

Question. Rehana did an experiment to see if some liquids mix with liquid X.  Her results are given below in the table. What can Rehana say from this?

(a) Liquid X does not mix with any other liquid.
(b) Liquid X can mix with most other liquids.
(c) Liquid X does not dissolve any solid.
(d) Liquid X does not mix with these four liquids.

Answer : D

Question. While making tea, why do we sometimes stir the tea with a spoon?
(a) to cool the tea faster
(b) to dissolve the tea leaves faster
(c) to dissolve the sugar faster
(d) to make the tea hotter

Answer : C

Question. Change of state is represented as follows When steam changes into water _____________ takes place.

(a) evaporation
(b) condensation
(c) melting
(d) sublimation

Answer : B

Question. Some solids directly change state and become gases without first becoming liquids. This is called sublimation. Which of these is an example of sublimation?
(a) A bottle of perfume is opened in the corner of a room. 
(b) If an ice-cube is left in the hot sun, nothing remains after an hour.
(c) When water is boiled, it changes to steam.
(d) Moth balls used to keep insects away disappear in a few days

Answer : D

Question. Ram bought a few cone ice creams for his family. On reaching home, he put them in the freezer compartment of his refrigerator. Why did Ram leave the ice creams in the freezer?
(a) The freezer can turn water into ice.
(b) The freezer is used for making ice creams.
(c) The freezer prevents ice cream from melting.
(d) The label on the cone ice cream asked him to do so.

Answer : C

Question. Which of these will change into liquid state immediately on heating?

Answer : B