NCERT Solutions for Class 6 Science<\/a> Chapter 14 Water Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.<\/p>\nWater NCERT Solutions for Class 6 Science Chapter 14<\/h2>\nClass 6 Science Chapter 14 Water Textbook Exercise Questions and Answers<\/h3>\n
Question 1.
\nFill up the blanks in the following:
\na. The process of changing of water into its vapour is called ……………..
\nb. The process of changing water vapour into water is called ……………..
\nc. No rainfall for a year or more may lead to …………….. in that region.
\nd. Excessive rains may cause ……………..
\nAnswer:
\na. evaporation or vaporisation
\nb. condensation
\nc. drought
\nd. flood<\/p>\n
Question 2.
\nState for each of the following due to evaporation or condensation:
\na. Water drops are formed on the outer surface of the bottle or any container containing cold water.
\nb. Formation of steam from wet clothes while they are ironed.
\nc. Appearance of fog on a cold winter morning.
\nd. Wiping of blackboard dries it up.
\ne. Steam rising from a hot girdle when water is sprinkled on it.
\nAnswer:
\na. Condensation
\nb. Evaporation
\nc. Condensation
\nd. Evaporation
\ne. Evaporation<\/p>\n
Question 3.
\nWhich of the following statements are \u201ctrue\u201d?
\na. Only during the monsoon season, the water vapour is present in the air.
\nb. Water vapourises into steam only from oceans, lakes and rivers but not from the soil.
\nc. The process of converting water into its vapour is called evaporation.
\nd. The process of evaporation takes place only in sunlight.
\ne. The water vapour condenses to form tiny droplets of water in the upper layers of air where it is cooler.
\nAnswer:
\na. False
\nb. False
\nc. True
\nd. False
\ne. True<\/p>\n
Question 4.
\nSuppose you want to dry your school uniform quickly. Would spreading it near an angithi or heater help? If yes, how?
\nAnswer:
\nYes, in order to dry the uniform faster, the uniform is spread near a heater since the rate of evaporation is faster at higher temperatures. The rate of evaporation is directly proportional to temperature. So, the uniform will be dried up quickly.<\/p>\n
<\/p>\n
Question 5.
\nTake out a cooled bottle of water from refrigerator and place it on a table. After some time, you will notice a puddle of water around the bottle on the table. Why?
\nAnswer:
\nSince the water bottle is at a very low temperature, the surface exposed is also very cold. As the cool surface is exposed, condensation of water vapour present in the air occurs. Now, the condensed water molecules spread around the bottle. So a puddle of water is noticed after some time.<\/p>\n
Question 6.
\nTo clean our spectacles, we often breathe out hot air on glasses to make them wet. Explain why the glasses become wet?
\nAnswer:
\nThe air we blow out contains water vapour. The water vapour condenses on the spectacles forming moisture and the glass is coated with a layer of minute water droplets. With the addition of small amount of water, we can easily clean the spectacles.<\/p>\n
Question 7.
\nHow are clouds formed?
\nAnswer:
\nThe water present on the earth\u2019s surface evaporates due to heat radiated by the sun. The water vapour present in the air condenses to form tiny droplets of water at high altitudes which in large quantity looks as clouds. Thus, clouds are formed by the condensation of water vapours available in the air at high altitudes.<\/p>\n
Question 8.
\nWhen does a drought occur?
\nAnswer:
\nWhen there is no rainfall for many years over a long period of time then there will arise a scarcity of water in that locality or region. This leads to drought.<\/p>\n
NCERT Extended Learning Activities and Projects<\/span><\/p>\nQuestion 1.
\nList three activities in which you can save water. For each activity describe how you would do it.
\nHint:
\nWe can save water by rainwater harvesting, using pre-used water for watering plants and preventing water pollution in rivers, lakes, etc.<\/p>\n
Question 2.
\nCollect pictures relating to floods or droughts from old magazines or newspapers. Paste them in your notebook and write about the problems that people would have faced.
\nHint:
\nDo it yourself.<\/p>\n
<\/p>\n
Question 3.
\nPrepare a poster on ways of saving water and display it on your school notice board.
\nHint:
\nDo it yourself.<\/p>\n
Question 4.
\nWrite a few slogans of your own on the topic \u2018Save Water\u2019.
\nHint:
\nDo it yourself.<\/p>\n
Question 5.
\nCan the interlinking of rivers be a solution for mitigation of flood? Discuss.
\nHint:
\nYes, it can help in mitigation of flood as the excess water will distribute over a larger area leading to better maintenance of water levels during heavy rainfalls.<\/p>\n
Activity 1<\/span><\/p>\nObjective: To estimate how much water do we need for our daily activities.
\nProcedure:<\/p>\n
\n- List all the activities for which you use water in a day.<\/li>\n
- Measure the amount of water used for each activity by all the members of your family in a day.<\/li>\n<\/ul>\n
Observations: Estimation of the amount of water used by a family in a day:
\n
\nConclusion: A family of four requires about 502 litres of water per day.<\/p>\n
Sources of Water: Ponds, wells, streams, lakes and rivers are the different sources of drinking water. Drinking water is called as potable water. Oceans and seas supply water to other water bodies through water cycle.<\/p>\n
States of Water: Water exists in three different states.
\ni. Water can occur in the solid state. Solid state can be represented by ice, snow or hail.
\nii. Water can occur in the liquid state. Liquid state of water can be represented by river, rain or sea.
\niii. Water can occur in the gaseous state. Gaseous state of water can be represented by water vapour.<\/p>\n
Three states of water are inter-convertible
\ni. Solid form of water can be converted into liquid form by heating. This is called melting.
\nii. Liquid form of water can be converted into gaseous form by heating. This is called vapourisation or evaporation.
\n
\niii. Gaseous form can be converted into liquid form by cooling and the process is called condensation.
\niv. Liquid form can be converted into solid form by freezing.<\/p>\n
Water cycle: The cyclic movement of water from the atmosphere to the Earth and back to the atmosphere through various processes is called as water cycle. Different steps of water cycle include evaporation, transpiration, condensation, precipitation and surface run-off.
\n
\ni. Evaporation: The water present on the surface of oceans evaporates by the sun\u2019s heat. This process of conversion of water from liquid state to vapour state is called evaporation. Evaporation also takes place from wet clothes, fields, ponds, lakes and rivers.<\/p>\n
<\/p>\n
Activity 2<\/span><\/p>\nObjective: To show that evaporation of water occurs in sunshine as well as in shade but it is faster in sunshine.
\nMaterials required: Two similar plates and water.
\nProcedure:<\/p>\n
\n- Take two similar plates.<\/li>\n
- Place one of the plates in sunlight and keep the other under shade.<\/li>\n
- Now, pour equal amount of water in each of the plates. You can use a cap of a bottle to measure water.<\/li>\n
- Make sure that water does not spill over.<\/li>\n
- Observe the two plates after every 15 minutes.<\/li>\n<\/ul>\n
<\/p>\n
Observations: Water kept in sunlight evaporates faster than that kept in shade.
\nConclusion: In sunlight, evaporation takes place faster because sunlight produces a higher temperature. In shade, evaporation takes place slower because of lower temperature in shade. Evaporation takes place continuously from all the open surfaces of water at all temperatures.<\/p>\n
ii. Transpiration: Plants take in water from the soil to prepare their own food and also for other life processes. They release excess water into air through leaves in the form of water vapour by the process of transpiration.<\/p>\n
iii. Condensation: The evaporated water is carried away by warm air. As the warm air moves higher from the surface of the Earth, it starts to cool down. This water vapour condenses to form tiny water droplets which float in air to form clouds or fog.<\/p>\n
iv. Precipitation: When droplets of water present in clouds unite to form large sized drops of water, being heavy, they begin to fall. This falling of water drops from clouds is called precipitation. Precipitation may occur in the form of:<\/p>\n
\n- Rain: If water droplets fall in form of liquid on the surface of the earth, it is called rain.<\/li>\n
- Hail or snow: Precipitation may be in the form of frozen or solid form. If the size of frozen water drops is large, the precipitation is called as hail. If precipitation is in the form of light flakes, it is called snow.<\/li>\n
- Dew: Water droplets, especially during winter nights, formed by water vapour present in the air, are called as dew.<\/li>\n<\/ul>\n
Activity 3<\/span><\/p>\nObjective: To study how are clouds formed.
\nMaterials Required: Glass and ice cubes.
\nProcedure:<\/p>\n
\n- Take a glass half filled with water.<\/li>\n
- Wipe the glass from the outside with a clean piece of cloth.<\/li>\n
- Add some ice into the water. Wait for one or two minutes.<\/li>\n
- Observe the changes that take place on the outer surface of the glass.<\/li>\n<\/ul>\n
\nDrops of water appear on outer surface of the glass containing water with ice
\nObservations: The puff of air around the glass becomes hazy\/cloudy. This is the cloud formed.
\nConclusion: The cold surface of the glass containing ice water cools the air around it, and the water vapour of the air condenses on the surface of the glass.<\/p>\n
v. Surface run-off: Some amount of rainwater is absorbed by the soil and settles down as groundwater. Most of the rainwater flows down the hills and mountains to collect into rivers, lakes or streams. Rain also washes away the topmost layer of the soil into water bodies.
\n<\/p>\n
Importance of water cycle in nature<\/p>\n
\n- Water cycle makes fresh water available in the form of rains.<\/li>\n
- Water cycle keeps the amount of water on the earth\u2019s surface constant. This is because the water removed from the earth during evaporation is put back to earth during rain and snowfall.<\/li>\n
- Water cycle plays an important role in regulating weather.<\/li>\n<\/ul>\n
Groundwater: The water that seeps into the ground and gets accumulated there is known as groundwater. Groundwater is the source of water in wells and lakes. Groundwater is withdrawn through hand pumps and tube wells.<\/p>\n
Flood: Floods are caused by rise in the water level in ponds and lakes due to heavy rainfall. The excess rain water flows on to the land causing floods. Floods make the soil water-logged. Floods affect normal life by disturbing everything which comes in its way. Floods wash out the living beings such as plants, fish, other animals, etc. Floods cause heavy loss to human life. Floods cause uprooting of trees. They wash away the crops. They result in shortage of food supply.
\n
\nDroughts: Droughts are the conditions which involve abnormally long period of insufficient or no rainfall. Droughts are caused due to lack of rains. Drought condition results in drying up of wells, lakes, ponds and thereby creating water scarcity. Droughts result in the evaporation of water from the soil leaving the soil dry and patchy.
\n<\/p>\n
Effects of droughts<\/p>\n
\n- Droughts result in mass death of plants and animals due to dehydration.<\/li>\n
- It affects agriculture and lessen food production.<\/li>\n
- It results in the death of animals and birds which provide us animal products like milk, meat and eggs. This scarcity of food results in the famine.<\/li>\n
- Droughts result in forest fires caused by enormous amount of heat from scorching sun.<\/li>\n<\/ul>\n
Water Conservation: Water is an essential natural resource. There exists no life without water. Water is so precious that it has to be conserved. Avoiding water wastage is also a kind of water conservation. Conservation programmes can be successful, if all people follow them faithfully.<\/p>\n
How to Conserve Water: Excess rainwater running in the rivers is stored in huge and special structure called as dams. Dams are huge structures built on rivers to hold back excess water. Dams prevent areas from flooding by storing large amount of water. Dams provide water for irrigating fields, domestic use and also drinking water for some areas.<\/p>\n
Drinking water should not be wasted to water the plants. Water bodies should not be polluted in order to get pure water. Water should not be wasted during irrigation of fields. Modem methods like spraying, sprinkling or drip irrigation should be used. Water should be used judiciously to avoid wastage. Destruction of trees should be controlled to increase the rainfall.<\/p>\n
Rainwater harvesting: Rainwater harvesting includes collection and storing of rainwater from the roofs of houses and huge constructions. This is also called as rooftop rainwater harvesting. Constant use of freshwater from the ground results in water scarcity. Rainwater harvesting increases the level of underground water.
\n<\/p>\n
Technique involved in rainwater harvesting:<\/p>\n
\n- Rainwater is collected at the rooftop.<\/li>\n
- It is allowed to flow into pipes.<\/li>\n
- It is filtered through wire mesh.<\/li>\n
- It is allowed to pour into an underground tank setup to store rainwater. These tanks contain layers of sand, gravel, charcoal that will filter the dirt and other impurities from rainwater. This water seeps back into the ground slowly to increase the level of groundwater table.<\/li>\n
- Second technique of rain water harvesting is to allow rainwater to go into the ground directly from the roadside drains.<\/li>\n<\/ul>\n
Class 6 Science Chapter 14 Water Additional Important Questions and Answers<\/h3>\n
Very Short Answer Type Questions<\/span><\/p>\nQuestion 1.
\nName two processes which are responsible for the formation of clouds.
\nAnswer:
\nEvaporation and transpiration.<\/p>\n
Question 2.
\nWhat happens to plants when they are not watered?
\nAnswer:
\nIf plants are not watered, they would wither. The seeds would not germinate and plants would not grow well.<\/p>\n
<\/p>\n
Question 3.
\nExplain what you mean by evaporation.
\nAnswer:
\nThe process of changing water (liquid form) into water vapour (gaseous form) is called evaporation.<\/p>\n
Question 4.
\nWhat happens to the potted trees when they are over watered? Why?
\nAnswer:
\nWater logging takes place and the plant may die as roots are unable to take oxygen from the soil.<\/p>\n
Question 5.
\nWhat would have been the consequence if the water was not recycled in nature by the water cycle?
\nAnswer:
\nThere would be no water available for use. Most of the natural phenomenon would be affected.<\/p>\n
Question 6.
\nWhy we rarely notice water vapour from a bucket full of water?
\nAnswer:
\nWe rarely notice water vapour from a bucket full of water because evaporation of water is a very slow process.<\/p>\n
Question 7.
\nWhy does a mist of tiny water droplets form when we breathe out on a window in winter?
\nAnswer:
\nWhen our warm breath touches a cold window, it condenses and forms a mist of tiny water droplets.<\/p>\n
Question 8.
\nIn which forms does water exist on the earth?
\nAnswer:
\nWater exists on the earth in all the three physical forms: ice (solid), water (liquid) and water vapour (gas).<\/p>\n
Question 9.
\nHow is snow or hail formed?
\nAnswer:
\nWhen water droplets freeze in the air and begin to fall, it is called hail or snow.<\/p>\n
Question 10.
\nWhat is precipitation?
\nAnswer:
\nWhen water drops come together in the air and become heavy, they begin to fall. This falling of water drops is called precipitation.<\/p>\n
<\/p>\n
Question 11.
\nWhat is the importance of convertibility of water from one state to another state?
\nAnswer:
\nThe easy convertibility of water from one state to another state makes its availability in all parts of the earth and throughout the year.<\/p>\n
Short Answer Type Questions<\/span><\/p>\nQuestion 1.
\nWhat are the two main functions of water for living organisms?
\nAnswer:
\nThe two main functions of water for living organisms are:<\/p>\n
\n- Water is very essential for the growth of plants, germination of seeds and in photosynthesis process.<\/li>\n
- Water is also very essential for the transportation of goods and people.<\/li>\n<\/ol>\n
Question 2.
\nWhy is sea water not used for domestic use?
\nAnswer:
\nSea and ocean water contains huge amounts of different types of salts. Because of the presence of these salts, the ocean water is salty and cannot be used for any domestic purpose such as drinking, washing and for irrigation purposes. So, only water from lakes, rivers, ponds and rainwater harvesting are used for domestic purposes.<\/p>\n
Question 3.
\nWhy does the water which is spilt on the floor disappear after a period of time?
\nAnswer:
\nDue to the process of evaporation, the water spilt on the floor is converted into water vapour. So it disappears after a period of time.<\/p>\n
Question 4.
\nHow does heavy rain affect us?
\nAnswer:
\nHeavy rains may cause:<\/p>\n