Haryana State Board HBSE 6th Class Science Solutions Chapter 14 Water Textbook Exercise Questions and Answers.
Haryana Board 6th Class Science Solutions Chapter 14 Water
Fill up the blanks in the following:
(a) The process of changing of water into its vapour is called ……………. .
(b) The process of changing water vapour into water is called …………… .
(c) No rainfall for a year or more may lead to ………….. in that region.
(d) Excessive rain may cause …………. .
State for each of the following whether it is due to evaporation or condensation.
(a) Water drops appear on the outer surface of a glass containing cold water.
(b) Steam rising from wet clothes while they are ironed.
(c) Fog appearing on a cold winter morning.
(d) Black board dries up after wiping it.
(e) Steam rising from a hot girdle when water is sprinkled on it.
Which of the following statements are “true”?
(a) Water vapour is present in air only during the monsoon.
(b) Water evaporates into air from oceans, rivers, and lakes but not from the soil. water level would lower down. It will result into drought.
(c) The process of water changing into its vapours, is ailed evaporation.
(d) The evaporation of water takes place only in sunlight.
(e) Water vapour condenses to form tiny droplets of water in the upper layers of air where it is cooler.
Suppose you want to dry your school uniform quickly. Would spreading it near an anghiti or heater help? If yes, how?
Yes, if we want to dry our school uniform quickly, we should spread our clothes near a anghiti or heater. Because near anghithi or heater, temperature is more, which helps water evaporation from the clothes and they dry quickly.
Take out a cooled bottle of water from refrigerator and keep it on a table. After some time you notice a puddle of water around it. Why?
When we keep a bottle of water taking out from refrigerator we notice some puddles of water around it. This is because the water-vapour near the surrounding atmosphere, condenses and deposites around the cooled water bottle. Water vapour always remains in the atmosphere.
To clean their spectacles, people often breathe out on glasses to make them wet. Explain why the glasses beomes wet?
When we breathe on the spectacles, water vapours comes out from our breathe, and they condenses into water droplets when they come in contact of glass, because the glasses are cooler than the water vapours. So the glasses becomes wet, due to water puddles.
How does clouds formed?
The water vapours that goes into air rises up along with air. As the air moves up, it gets cooler and cooler. At sufficient heights, air becomes so cool that the water vapour present in it condenses to form tiny drops of water called droplets. These droplets are very small, much smaller than even a grain of sand. These droplets are so small that lakhs of them together would form a drop of water.
These tiny droplets remain suspended in the air and moves along with it. When these water droplets in the air come closers they may combine to form slightly bigger droplets. In this way their sizes may become larger. Once the size of the droplets become larger than a definite size, they appear to us as clouds.
When does a drought occur?
If it does not rain in a region for a year or more. The soil continues to lose water by evaporation and transpiration. Since it is not being brought back by rain, the soil becomes dry. The water level of water in ponds and wells of the region goes down and some of them may even dry up. The ground water may also become scarce. This may lead to drought.
HBSE 6th Class Science Water Important Questions and Answers
Very Short Answer Type Questions
Define the term ‘cycle’.
It is an event or phenomenon which repeats itself after sometime.
Name some activities in our daily life where we use water.
We use water in our daily life in various activities such as: drinking, bathing and washing of clothes.
What is the main source of water?
Oceans are the main source of water.
Define the term ‘evaporation’.
The process of changing water from its liquid form to its vapour is known as evaporation.
Is evaporation a slow process or fast process?
Evaporation is a slow process.
What is transpiration?
Plants lost their excess water through their leaves into the air in the vapour form. This process is called transpiration.
Name two processes through which water vapour add conti-nuously into the air.
The two processes are:
The process of conversion of water vapours into liquid form of water is called ; condensation.
What is fog?
The fog in winter is due to condensation of water vapour in air near the , surface of the earth.
What is precipitation?
When water drops come together in the air becomes heavy and begin to fall, Falling of water drops is called precipitation.
How is snow or hails formed?
When water droplets freeze in the air and begin to fall is called hails or snow.
Define water cycle.
The water in its vapour form goes to air by evaporation and transpiration forms cloud and then comes back to the surface of the earth through the process of condensation and precipitation. This process is called water cycle.
Name three states of water.
The three states of water are:
(iii) gaseous state.
What is the importance of convertibility of water from one state to another state?
The easy convertibility of water from one state to another state makes its availability in all parts of the earth and throughout the year.
What is the percentage of water that is available for our use?
Only a tiny fraction about 0.01% of total water is used by human beings.
What would happen if we do not water plants?
Water is essential for plants for their food preparation. So the plants will die without water.
List two sources of water on the earth.
(i) Underground water
(ii) surface water.
Where do we get water for our daily use?
We get water from well, rivers and ponds.
During melting of ice, the temperature of the system changes/remains unchanged.
List the sources of water on the earth.
Sources of water on the earth are: Rivers, ponds, lakes, well, spring and rain water.
Write the chemical formula of water.
Name two sources of natural water.
(i) River water
(ii) Lake water.
Name two solid forms of water.
Snow, hails and frost.
Name universal solvent.
Water is a universal solvent.
What is saline water?
A sample of water contains more than 2% dissolved salts are called saline water.
Name the process by which saline water is made potable.
What do we use water for?
We use water for drinking, bathing and cleaning purposes.
Give two uses of water in your home.
(i) Cooking of food
(ii) Cleaning of utensils.
What is the use of water in agriculture?
In agriculture, water is required to produce grains.
From where do we get fresh water supply?
The ultimate source of fresh water supply is oceans.
Who supplies water to lakes and ponds?
Oceans supply water to lakes and ponds.
What will happen if we do not water the plants in the pot?
Water is essential for plants, for the preparation of their food. Without water, the plants will die.
List the sources of water for your daily use.
We get water for daily use from wells, lakes, rivers, ponds and streams.
List the sources of water on the earth.
Sources of water on the earth are: Rivers, lakes, ponds, well, spring, sea water, rain water and ocean water.
List the salts that can be obtained from the sea.
Common salt, sodium bromide, magnesium chloride and potassium iodide.
Explain the term ‘salinity’.
The rain water dissolves large amounts of salts, and it becomes salty. This is called salinity of water.
Write two uses of water in plants.
(i) They use water in photosynthesis.
(ii) Water is essential for germination of seeds.
Name two sources of natural water.
River water, lake water and stream water.
Name two solid states of water.
What is saline water?
A sample of natural water which contains more than 2% of dissolved salts, especially common salt is called saline water.
Short Answer Type Questions
How do fish and aquatic plants survive in water?
Fish and aquatic plants needs oxygen to survive. Oxygen is slightly soluble in water. They get this dissolved oxygen for their survival.
How are clouds formed?
Water vapours being lighter, rise up in the atmosphere. At the upper layer, they are condensed into tiny water droplets and form clouds. These clouds while falling down cause rains.
Give four physical properties of water.
Physical properties of water:
1. It is a colourless liquid.
2. It freezes at 0°C and boils at 100°C.
3. Bad conductor of electricity.
4. It has a maximum density ofll cm3 at 4°C.
Define water cycle.
Evaporation of water from oceans, ponds, rivers and lakes and from roads and streets to form cloud by condensation at higher altitude. When clouds rain, the rain water flows into the seas and oceans through rivers and streams. Some water percolates into the soil to form underground water. It comes again out in the form of spring and well. This is called water cycle.
Water is called a universal solvent. Give reasons.
Water is called universal solvent because it dissolves any things in it. Many things dissolve in water as the time passes. So it is called universal solvent.
State different uses of water.
Uses of water:
(i) We use water for drinking, bathing, cooking and cleaning of clothes.
(ii) Water is used in agriculture to produce food.
(iii) It is used in industries for carrying out various activities.
(iv) It is used for making electricity from flowing water.
(v) In thermal power stations, water is used to rotate generators through steam to produce electricity.
(vi) In railways, it is used to move railway engines. In factories, it is used in boilers to produce hot water and steam for running machines.
What are the different sources of water?
Different sources of water are:
(vi) Well and dam water.
Write importance of water for sustaining life.
Importance of water:
(i) Water is used by the organisms to transport soluble food materials to the cells.
(ii) It carries waste materials produced within the cells which are excreted out by the living beings.
(iii) It carries oxygenated red bloods to cells and tissues ofliving beings and brings back carbon dioxide produced during respiration and excreted out from the body.
(iv) Plants use enormous water during photosynthesis.
(v) It maintains body temperature.
(vi) Water is essential for germination of seeds.
How does rain water become saline?
Water is a universal solvent, because it dissolves a large number of substances. When rain falls, it dissolves common salts and many other substances and minerals present on the earth. The rain water passes through different layers of earth, rocks, dissolves large amount of salt and other minerals. Thus it becomes salty.
How will you show the presence of water in air? .
Take some pieces of ice in a beaker and keep it for sometime. After some time, we will observe that small water drops are formed on the cold outer surface wall of the beaker. These water drops are formed by the condensation of those water vapours which were present in air around beaker. This shows that water is present in air.
What are natural calamities?
The conditions of floodings and drought ai’e called natural calamities.
What are the factors responsible for flooding?
There are many factors for flooding like intensity and duration of rainfall, soil condition and presence of plants or trees on the grounds.
Give some uses of water in our houses.
We use water in our houses for “many purposes; we need it for drinking, bathing, washing our clothes. We also use water for cooking, cleaning of utensils, watering of plants and other everyday activities.
How is water essential for plants?
Water is essential for agriculture to produce grains; It is also required for growing plants that gives us fibres of cotton and jute. Water is required for the growth and in the process of photosynthesis for preparing their food. Germination of seeds requires water.
Who supplies water to rivers, lakes, ponds and wells?
Oceans and seas are major sources of water on the earth. The water cycle fully depends upon oceans and seas. Rain is possible only due to water cycle and supplies water to rivers and ponds etc. Indirectly, ocean supplies water to these resources.
Define ground water.
‘The ground water is actually rain water which mainly comes from seepage of water accumulated under the ground. Rain water percolates into the soil and reaches under the ground where water quantity increases and air decreases. This reserve water under the ground is called ground water.
We should use ground water judiciously. Why?
If large quantity of ground water is taken out for various purposes, the water level goes down. Thus there will be shortage of water and it is not possible if we continuously use this water. So we should use ground water very carefully.
How are lakes and ponds formed?
Lakes and ponds are small reservoirs of water. These are created by collection of rain water in low lying areas. Seepage from the ground water reserves also adds to the water in lakes and ponds.
What will happen if there is no rain at all?
Rain is an important source of natural water. If there is no rain, the soil will lose its water by evaporation and become dry. Water will also be lost through transpiration process of plants. Rivers, ponds and wells will dry and the water level would lower down. All this will affect animals, humans and wild plants. If it continues for one or tw o years in continuation, it results into drought.
Long Answer Type Questions
What do you mean by water cycle in nature?
Water constantly moves from the earth to the air and back again. The constant circulation of water is known as the water cycle.
The water in seas, rivers, lakes, ponds „r streams evaporates because of the heat of the sun. Plants also give out large amounts of water from their leaves. The water vapour rises up. The air higher’ up in the atmosphere is cooler. This cools the water vapour and it condenses to form tiny drops of water on dust particles. These drops of water together form clouds. As the clouds get cooled further, the water drops become bigger and heavier. When they become too heavy, they fall to the earth as rain.
The rain water enters the seas, rivers, lakes, ponds and streams and then evaporates again. Thus the water cycle in nature goes on.
How can we conserve the precious water?
Water can be conserved by the following methods:
(i) We should use water very judiciously.
(ii) We should not waste water during its consumption.
(iii) We should not use drinking water in garden for watering plants.
(iv) We should not throw waste products into water resources.
(v) Water is used through pipes and spraying in agriculture.
(vi) Industrial wastes and effluents should not be released into rivers.
(vii) Ground water should be used when necessary. Leakage of taps should be stopped. In this way, we conserve water.
Water Class 6 HBSE Notes
- Water is essential for all living beings. Water is essential for sustaining life. Water vapour is always present in the air.
- Evaporation of water changes it from its liquid to gaseous state. Evaporation is a slow process.
- Evaporation of water is a continuous process that takes places at all places.
- Large amount of water evaporates into air from oceans, rivers, lakes, ponds and other water bodies and also from the soil.
- Plants release water vapours into air by the process of transpiration.
- The process of conversion of water vapour into liquid water is called condensation. Water vapours condense to form tiny droplets of water in the upper layers of air where it is cooler.
- Clouds appear in the sky when water droplets in air become larger than certain size.
- Falling of water drops from the clouds is called precipitation.
- The process of evaporation, transpiration, condensation, precipitation of water and its down hill flow to the oceans constitute the water cycle.
- Cycling of water between oceans and land ensures availability of water for all living organisms on the earth.
- Water exists in three states, that is solid, liquid and gaseous.
- Lakes, ground water and ice caps are some sources of water. Well water and spring water are examples of ground water.
- Water is a universal solvent, because it dissolves a large number of substances.
- Ocean water is highly saline. This water is harmful for agricultural purpose, animals and for human use.
- Pure water is colourless, odourless and tasteless liquid. Water becomes tasty due to dissolving of some gases such as C02 in it.
- Water dissolves oxygen gas due to which aquatic plants and animals respire. Presence of dissolved carbon dioxide is a source of food for aquatic plants.
- Water cycle helps in replenishing water sources and maintaining global weather.
- Evaporation of water from sea and other water bodies forms clouds at higher altitude. Clouds give rains and rain water flows back into the sea in the form of streams and rivers. Some rain water percolates through the soil to form underground water. This underground water comes up again and rushes out in the form of springs or is drained out as well water. This is called water cycle.
- There are two main natural sources of water: (i) Underground water, (ii) Surface water. Underground water is free from impurities.
- It is mainly of two types: (i) Well water, (ii) Spring water.
- Surface water is present on the surface of the earth. It is of three types: (i) rain water, (ii) river and lake water, (iii) sea water.
- Water is precious. It is one of the most wonderful gifts of nature.
- The total amount of water on the earth remains same but its distribution in different regions is different.
- We need water for various purposes, like drinking, bathing, washing our clothes, for cooking food, cleaning of utensils, watering of plants and other everyday activities.
- Water is required in agriculture to produce grains. It is also necessary for growing plants that gives us fibres and jute. Fibres are used for making clothes.
- Oceans and seas contain most of the water on the earth.
- Oceans and sea water is not fit for drinking and for agriculture purposes due to large amount of salt in it.
- Snow is another source of water. Snowmelts slowly and this water flpws down in the form of streafhs and rivers. Streams and rivers are another source of water.
- Most of the water which human beings use for drinking, washing and farming comes from rivers and streams.
- Water below the ground is known as underground water. This is mainly rain water that comes from seepage of water accumulated under the ground. The level below the ground where air is very less and only water is present is called water table.
- Lakes and ponds are small reservoirs of water. These are created by collection of rain water in low laying areas.
- Rain is a very important source of water for us. All resources of water are fed mainly by rains.
- If it does not rain for one or two years, soil will lose its water by evaporation and become dry. Rivers, ponds and lakes will dry and the
- The results of drought may be that no crops, food and fodder will decrease and humans and animals will die.
- In case of heavy rains, water level increases and flood occurs. Due to lack of air in soil due to heavy rains animals suh as earthworm, rats and snakes come out from the soil. Due to heavy rains, crops are also destroyed.
- Conditions of flood and drought are called natural calamties.
- Conservation of water is essential for sustaining life on the earth. Due to increasing population and increasing industrialisation and urbanisation, water requirements are also increasing.