Water and Life Notes Questions and Answers Class 5 Basic Science Chapter 3 Kerala Syllabus

Reviewing SCERT Kerala Syllabus 5th Standard Basic Science Notes Pdf and Class 5 Basic Science Chapter 3 Water and Life Question Answer Notes SCERT Solutions Pdf can uncover gaps in understanding.

Water and Life Class 5 Questions and Answers Notes

Class 5 Basic Science Chapter 3 Question Answer Notes Pdf  Water and Life

Basic Science Class 5 Chapter 3 Question Answer Kerala Syllabus

Let Us Assess

Question 1.
The change in state of water is illustrated below. Complete the flowchart by adding appropriate words.

Answer:

Question 2.
Complete the idea chart made on water.

Answer:

Question 3.
Examine the test report on water quality made on three different sources. Analyse the table and write your findings.

Property	River	Pond	Well
Colour	Muddy	Muddy	Clear
Odour	Foul odour	Foul odour	No odour
Organic waste	Yes	Yes	No
Chemical waste	Yes	Yes	No

a) Which source of water is the safest to drink?
b) Can we make river and pond water potable? How?
c) What can we do to prevent pollution of water sources?
Answer:
a) Well
b) Yes, Disinfection in water treatment plants can make them safe to drink.
c)

• Avoid dumping wastes into the waterbodies.
• Avoid dumping factory waste into the waterbodies.
• Make sure that fertilisers and pesticides do not flow into the water bodies.
• Use toilets and other sanitation facilities.

Question 4.
The properties of water are listed. Find out and complete the table with suitable details from daily life.

Answer:

Properties of water	Situation
Conducts heat	Cooking food items
Maintains level	Levels are set in building construction
Universal solvent	Preparing various solutions like salt solution
Ability to vapourise	Drying up of wet clothes, Drying up of washed surfaces

Extended Activities

Question 1.
What is the main source of drinking water in your locality?
Let’s conduct a surwey. Information should be collected about the sources of drinking water in your house and three neighbouring houses.

Drinking water source	In my house	Neighbourhood houses
		House 1	House 2	House 3
Well
Public water supply system
Borewell
Rain water storage tank
Other sources

Answer:

Drinking water source	In my house	Neighbourhood houses
		House 1	House 2	House 3
Well	✓	✓	✗	✗
Public water supply system	✓	✓	✓	✗
Borewell	✗	✗	✓	✗
Rainwater storage tank	✗	✗	✗	✓
Other sources	✗	✗	✗	✗

Most of the houses use public water supply systems to get water to satisfy their needs. Wells are also seen in common. Rainwater storage tanks and borewells are used by very few people in our locality.

Question 2.
Study and prepare a note on your school’s water usage.
Information to be collected

• What are the water sources at the school?
• How much water is used per day?
• For what needs?
• For what purpose water is most used?
• What practical suggestions can you make for reducing water use at present?

Answer:
Water Usage at Our School

• Water Sources: Our school primarily uses water from two sources: a municipal supply and a borewell on campus.
• Daily Water Usage: On average, our school uses about 5,000 litres of water per day.
• Needs: The water is used for various purposes such as drinking, cooking in the kitchen, cleaning classrooms, toilets, and watering plants.
• Most Used Purpose: The majority of water is used for maintaining cleanliness, including cleaning classrooms and toilets.

Suggestions for Reducing Water Use:

• Fix any leaky taps or pipes promptly to avoid wastage.
• Encourage students and staff to turn off taps tightly after use.
• Reuse water where possible, like using water for cleaning to watering plants.
• Educate everyone about the importance of conserving water and involve them in initiatives to save water

Question 3.
Design an apparatus to demonstrate experimentally that water maintains its level.
Answer:
Procedure:
1. Set up the Apparatus:

• Place the transparent container on a support stand or a flat surface.
• Fill the container with water up to a marked level (you can use a marker to make a clear indication).
• Insert one end of the flexible tubing into the container, ensuring it reaches the bottom.
• Keep the other end of the tubing above the water level.

2. Observe the Water Level:

• Take note of the water level in the container and the end of the tubing.

3. Add Food Colouring:

• If desired, add a few drops of food colouring into the water to make it easier to see.

4. Manipulate the Tube:

• Gently bend or curve the tubing without altering the height of the open end above the water level.

5. Observe Changes:

• Observe how the water level inside the tubing remains the same as the water level in the container.
• You can measure the height of the water column inside the tubing at different points to confirm that it matches the water level in the container.

Water and Life Notes Questions and Answers

Question 1.
Do you get the water regularly in the same way?
Answer:
Yes, It’s delivered to homes and buildings through a system of pipes managed by local authorities.

Question 2.
What are the other sources of water you depend on?
Answer:
Wells, Tubewells, Rainwater, Lakes, Ponds, Streams etc.
Take a look at the table showing the approximate amount of water used by one person for various purposes.

Approximate daily use of water

Use of water	Quantity (in litres)
To drink	2.5 – 3.5
To cook food	3.0 -4.0
To wash vessels	6.0 – 8.0
To bath and to wash clothes	30.0
For sanitation	50.0
For other purposes	30.0
Total	121.5-125.5

Question 3.
Compare your daily use with the usage in the given table.
Answer:

• Toilets: A single flush can use between 3 and 7 litres of water exclamation.
• Showers: A five-minute shower can use between 60 and 100 litres of water.
• Clothes washer: A typical clothes washer uses between 50 and 100 litres of water per cycle
• Dishwasher: A dishwasher can use between 30 and 50 litres of water per cycle.
  We can control and limit the use of certain things, but not the drinking water.

Eg: Taking shorter showers, running washing machines and dishwashers only when they are full. increasing demand and decreasing availability. The availability of fresh water is decreasing due to an increase in population and an increase in the level of water pollution, it is estimated that 200 crore people in the world do not have access for a sufficient amount of fresh water. If this situation continues, it is expected that the water shortage will become more severe in the coming years. Millions of people die all over the world every year due to diseases caused by water pollution.

Question 4.
For what purpose do you use the water most? How many litres of water do you use approximately in your home per day? Find out and write in your science diary.
Answer:
For bathing and washing clothes. On average, a typical household might use anywhere from 100 to 400 litres of water per person per day, but this can vary widely.

Question 5.
What is the importance of water in our body?
Answer:
Most of the body activities need water. Water keeps us hydrated, cools us down, helps move nutrients, keeps joints healthy, and aids digestion. See the approximate amount of water in our body.

Water is an important component of the human body.
Water is essential for all life functions.

Water in plant
Plants also need water.
What are the functions of water in plants? Look at the illustration.

All living beings need water for life functions.

Question 6.
Did you notice the child’s opinion? Do you agree with this statement f
Answer:
No. water that is colourless and odourless may contain disease-causing microorganisms and harmful chemical substances dissolved in it.
Some information from the water quality testing report is given below.

Tested Factor	Presence
Colour	No
Odour	No
Bacteria	Yes

Question 7.
What is the benefit of testing water like this? Discuss.
Answer:
The presence of bacteria in water can be detected.The salts present in water can also be identified.

Question 8.
Write the definition of pure water.
Answer:
Pure water is Water that is very clean and safe to drink. It doesn’t have anything else mixed in it that could make you sick.
To find out whether the water you are drinking is clean, take a sample of the water and send it to the quality testing labs in your locality to get a test report.

Does water have a shape?

Question 9.
Take water ¡n containers of various shapes. Is there a relationship between the shape of the water and the shape of the container?
Answer:
Water has no definite shape. So it takes the shape of the container in which it is filled.
Observe the shape of the water in each container and draw it in your science diary.

Question 10.
Which of the following objects will float in water? Mark your findings ¡n the table.

Objects	Finding
Stone
Balloon
Coin
Wood piece
Camphor
Plastic
Iron nail
Leaf
Wax
Ice

Answer:

Objects	Finding
Stone	Sink
Balloon	Float
Coin	Sink
Wood piece	Float
Camphor	Float
Plastic	Float
Iron nail	Sink
Leaf	Float
Wax	Sink
Ice	Float

Question 11.
We often utilise the ability of objects to float in water, don’t we? Write some examples for such situations.
Answer:
Rafting, Swimming. Boating. Playing with Paper Boats. Using a Life Jacket, Water Park Fun, Plastic balls fixed to the fishing nets.

Question 12.
Do all substances dissolve in water?
How do we find substances that do not dissolve in water?
Answer:
No. If the substance remains visible as solid particles or floats on the water’s surface without dissolving, it indicates that it is insoluble in water.

Question 13.
(Sugar, salt, vinegar, baking soda, detergent, kerosene, coconut oil, ‘ax. camphor, copper sulphate, potassium permanganate)
Which of the above substances dissolve in water?
Answer:
Sugar, salt, vinegar, baking soda, detergent, copper sulphate, and potassium permanganate are the substances soluble in water.

Question 14.
Are there any substances that do not dissolve in water? Conduct the experiment and list your findings.

Substances that dissolve in water	Substances that does not dissolve in water
• Sugar	• Wax

Answer:
Yes

Substances that dissolve in water	Substances that does not dissolve in water
Sugar	Wax
SaIt	Kerosene
Vinegar	Coconut oil
Baking soda	Camphor
Detergent
Copper sulphate
Potassium permanganate

Question 15.
You have seen that some solids and liquids dissolve in water. Do gases dissolve in water?
Answer:
Yes. Gas can dissolve in water.

Look at the picture

Question 16.
Where do the fishes in the aquarium get oxygen to breathe?
Answer:
Fishes breathe the oxygen dissolved in water.

Question 17.
Have you seen the bubbles coming out of the soda bottle when you open it? How is soda water made?
Answer:
Soda water is made by dissolving carbon dioxide gas in water. The bubbles are caused by the release of carbon dioxide gas when the soda bottle is opened.

Question 18.
What was dissolved when the lemon juice was prepared? Where did they dissolve in?
Answer:
Lemon and sugar are dissolved in lemon juice. They are dissolved in water.
A substance that dissolves is called a solute and the substance in which it dissolves is called a solvent. A solution is formed when the solute is dissolved in the solvent.
SOLUTE + SOLVENT , SOLUTION

Question 19.
List the solution, solute and solvent in each of the previous activity.

Solution	Solute	Solvent
Sugar Solution Soda	Sugar	Water

Answer:

Solution	Solute	Solvent
Sugar Solution	Sugar	Water
Soda	Carbon dioxide	Water
Salt Solution	Salt	Water
Vinegar Solution	Vinegar	Water
Baking Soda Solution	Baking Soda	Water
Detergent Solution	Detergent	Water
Copper sulphate Solution	Copper sulphate	Water
Potassium permanganate Solution	Potassium permanganate	Water

Question 20.
Find more substances that dissolve in water and expand the table.
Answer:
Lemon juice, Coffee, Corn hour, Food colour, Shampoo, Chocolate syrup, Fertilizer etc.

Question 21.
How do you remove jackfruit gum and tar if they stick?
Answer:
We can remove jackfruit gum and tar by applying kerosene or coconut oil.

Question 22.
Why can’t these be washed off with water?
Answer:
It’s because jackfruit gum and tar are not soluble in water.

Question 23.
What is the best way to remove ballpoint pen ink on clothes?
Answer:
Spray spirit or sanitiser and brush it well.

Question 24.
Are the substances soluble in water, soluble in kerosene and coconut oil too?
Let’s experiment.

Answer:

Solvent	Solute
	Sugar	Salt	Baking soda	Copper sulphate	Camphor
Water	soluble	soluble	soluble	soluble	insoluble
Kerosene	insoluble	insoluble	insoluble	insoluble	soluble
Coconut oil	insoluble	insoluble	insoluble	insoluble	soluble

Water has the ability to dissolve many substances.
Hence water is called the universal solvent.

Question 25.
Write more examples that take advantage of the dissolving capacity of water.
Answer:
To wash clothes, To prepare solutions having water as the solvent, To dilute acids, To clean apparatus used in laboratories.
Do the following experiment using water, sugar and ink.
Situation I
Take water in two glasses and mix sugar grains in one and powdered sugar in the other.
Observation I
Powdered sugar dissolves in water faster.
Situation 2
Take two glasses of water. Dissolve the sugar in the first glass with stirring, and dissolve the sugar in the second glass without stirring.
Observation 2
On stirring, sugar dissolves faster in water.
Situation 3
Take hot water in one glass. cold water in another glass and mix a drop of ink in each.
Observation 3
Ink dissolves faster in hot water.

Question 26.
Is there any difference in the speed at which sugar and ink dissolve?
Answer:
Ink dissolves faster than sugar in water.

Question 27.
Find out and write don the factors that affect the speed of dissolution of substances.
Answer:

• Powdered substances base a greater speed of solubility
• On strong stirring, the speed of solubility increases.
• On getting hotter, the speed of solubility increases

Question 28.
How is ice formed?
Answer:
Water solidifies to form ice. Ice is the solid form of water.

Question 29.
What are the uses of ice?
Answer:

• To preserve food items from spoiling.
• To prepare cold drinks, ice creams etc
• To go skating in ice-cold mountain ranges.
• Eskimos use ice to make houses in polar regions.

Question 30.
What happens ¡f the ice is left outside for a short time?
Answer:
Ice melts to water.

Question 31.
Prepare a note by observing changes that happen to ice in different situations.

Situations	Observations
1. When ice is kept in a vessel
2. When ice is heated
3. When the water in the vessel boils
4. When looking at the bottom of the lid of the vessel, after boiling the water

Answer:

Situations	Observations
1. When ice is kept in a vessel	Ice changes to water slowly
2. When ice is heated	Ice melts to water very fast
3. When the water in the vessel boils	Water changes to water vapour
4. When looking at the bottom of the lid of the vessel, after boiling the water	Water sticks to the surface

Question 32.
In many soluations we use the ability of water to conduct heat. Which are those situations.
Answer:
For cooking rice. To keep water in a hotter state. In vehicle radiators, To cool down hotter objects faster, In boilers used in factories. Haven’t you noticed that when water is heated, it rises up as steam?

Question 33.
What happens to the moisture in the wet clothes as they get dry? Discuss.
Answer:
It vapourises and mixes in the atmosphere.
The spreading of small particles of liquid from its surface to the surroundings is called vapourisation. As the substance heats up, the rate of vapourisation increases. Vapourisation occurs at all temperatures. Water is the only substance that exists ¡n nature ¡n all the three states : solid, liquid and gas.

Question 34.
Make the apparatus as shown in the picture. Pour water into any bottle and observe what is happening. Write your findings in your science diary.
Answer:
The water level in all the bottles is the same.

Question 35.
What will happen to the water level in the wells of the nearby houses when water bodies dry up?
Answer:
When water bodies dry up the water level lowers in the nearby wells.

Question 36.
ill the uncontrolled use of water by industries affect the available in that area?
Answer:
Yes. Uncontrolled use of water lowers the water level. As a result wells in nearby area does not get water.
Water maintains its level. This is a property of water.

Question 37.
What is the main body of water on Earth’?
Answer:
Sea.
Sea water contains large amounts of dissolved salts, so it cannot be used for daily needs. The water reaches these water sources through the rain. There are many water sources like wells, ponds, rivers, lakes, canals, tube wells, springs, rain etc.

Question 38.
Write down the sources of fresh water around you
Answer:
Wells, tubewells, springs, rain.

Water drop says
Living beings cannot live without us. As the water bodies get heated up, we rise into the atmosphere. We then get cooled and turn into rain clouds. Then small particles in the rain clouds combine together as raindrops and fall to earth. Thus we become part of water sources.

Living beings depend on the freshwater available on Earth. But some human activities are causing water pollution.

Observe the cases given below.

Question 39.
Conduct a class seminar on water pollution and its remedies.
Answer:
Causes of water pollution

• Washing of clothes and vehicles in rivers.
• Dumping domestic waste into the rivers.
• Dumping factory waste into the rivers.
• Giving cattles a bath in the rivers.
• Flow of fertilisers and pesticides from agricultural fields to the rivers.
• Dumping of human excreta into the rivers.

Remedies

• Avoid washing of clothes and vehicles in rivers.
• Avoid giving cattles a bath in the rivers.
• Adopt suitable methods for waste disposal in houses.
• Avoid dumping factory waste into the rivers.
• Use fertilisers and pesticides wisely.
• Use toilets and other sanitation facilities.

Question 40.
What other methods can be used for water storage?
Answer:
Water fence.

Question 41.
Find out the methods that are being used in your area.
Answer:
Rainwater storage tank, check dam, stone wall, well recharging.

Basic Science Class 5 Chapter 3 Water and Life Question Answer Notes

Question 1.
What is vapourisation? What happens to the rate of vapourisation as a substance heats up?
Answer:
The spreading of small particles of liquid from its surface to the surroundings is called vapourisation. The rate of vaporisation increases as the substance heats up.

Question 2.
How do builders use water to check if two points are at the same level?
Answer:
Builders fill a tube with water and place it between two points. If the water in the tube is at the same height as the reference point, then the two points are at the same level.

Question 3.
Why is water called the universal solvent?
Answer:
Water is called the universal solvent because it can dissolve many different substances.

Question 4.
how is ice formed?
Answer:
Ice is formed when water freezes arid turns from a liquid to a solid.

Question 5.
In what ways is vapourisation beneficial for our day-to-day life?
Answer:

• The mopped wet floor dries off
• The wetness in the washed vessels disappears after some time.
• Wet clothes dry out.
• Water in the lakes and soil always changes into water vapour.

Question 6.
The gum that sticks to the knife while cutting a jackfruit is removed using kerosene. Which property of kerosene is utilised here?
Answer:
Kerosene acts as a solvent here. The gum is soluble in kerosene. So the gum can be easily removed from the knife.

Question 7.
How is rain formed?
Answer:
As the water bodies get heated up, water rises into the atmosphere. Then the water gets cooled and turns into rain clouds. Then small particles in the rain clouds combine together as raindrops and fall to earth as rain.

Question 8.
When does water pollution occur?
Answer:
Water pollution occurs when harmful substances contaminate water, making it unsafe for plants, animals, and people.

Question 9.
Point out any two causes of water pollution.
Answer:

• Washing of clothes and vehicles in rivers.
• Avoid dumping factory waste into the rivers.

Question 10.
How does water reach different water sources?
Answer:
By rain.

Question 11.
Find out the odd one.
a) Buttermilk, spirit, tender coconut water
b) Rivers, borewells, lakes
Answer:
a) Spirit – others help the growth of plants.
b) Borewells – others are surface water sources.

Question 12.
Suggest the solutions for the scarcity of drinking water in your locality.
Answer:

• Do not waste water.
• Minimise the overuse of water.
• Restrict water-polluting activities.
• Restrict deforestation.
• Build rain pits, rainwater reservoirs, etc.

Question 13.
Categorise the following objects into float or sink in water?
(Paper, plastic bottle, copper wire, steel plate, ice cube, honey)
Answer:

Objects that float on water	Objects that sink in water
Copper wire	Paper
Steel plate	Plastic bottle
Honey	Ice cube

Question 14.
Categorise the following objects into soluble or insoluble in water?
a) Sugar syrup
b) Lemon juice
c) Table salt
d) Palm oil
e) Sugar candy
f) Chilli powder
g) Cement
h) Rice batter
Answer:

Objects soluble in water	Objects insoluble in water
Sugar syrup Lemon juice Table salt Sugar candy	Palm oil Chilli powder Cement Rice batter

Question 15.
You might have seen air pumps fitted in the aquariums. What is its need?
Answer:
Fishes breathe the oxygen dissolved in water. Due to continuous breathing, the amount of oxygen in water can be decreased even upto zero per cent. It leads to the death of fish. So, to ensure the availability of oxygen, aquariums are fitted with air pumps.

Question 16.
Check whether the statements given below are true or false. Correct the false statements.
a) When temperature increases, the solubility of substances decreases..
b) Vapourisation occurs when it is hot.
c) Water has the maximum heat-holding capacity.
d) Rainwater is the purest form of water available in nature.
e) The maximum amount of substance present in a solution ¡s the solute.
Answer:
a) False
When temperature increases, the solubility of substances also increases.
b) False
Vapourisation occurs all the time.
e) True
d) True
e) False
The maximum amount of substance present in a solution is the solvent.

Question 17.
Match the following

A	B
Universal solvent	Check dam
Water storage	Chemical fertilisers
Water pollution	Clouds
Water sources	Solutions

Answer:

A	B
Universal solvent	Check dam
Water storage	Chemical fertilisers
Water pollution	Clouds
Water sources	Solutions

Question 18.
The various stages in the purification of water are given in disorder. Place them in the right order.
A. Allow waste to settle.
B. Disinfect.
C. Distribute water to houses.
D. Filter out large debris.
E. Store in tank.
F. Strain through multi-layered sieves.
Answer:
D. Filter out large debris.
A. Allow waste to settle.
F. Strain through multi-layered sieves.
B. Disinfect.
E. Store in tank.
C. Distribute water to houses.

Question 19.
Answer the following
a. Which body part has the maximum water content in it?
b. Which of the following does not sink in water?
(ice, coin, stone, iron nail)
c. Which is the only substance in nature that can exist in solid, liquid and in gaseous state?
Answer:
a. blood – 94%
b. ice
c. water

Question 20.
Answer the following
a. What do you know about the shape of water?
b. Name the universal solvent.
c. What is the gaseous state of water?
d. Which is the main water body on earth?
e. What are the main components of a solution?
Answer:
a. Water has no shape. It takes the shape of the container in which it is kept.
b. Water.
c. Water vapour.
d. Sea.
e. Solute and solvent.

Question 21.
Some properties of water are given in the box. And also their situations in which they are used. Match them correctly.
(Dissolves substances, flows, carries heat, has no definite shape. takes the shape of the container, Exists in the solid, liquid and gaseous state)
a. For sweetening drinks.
b. Carried through pipes.
c. Can be collected ¡n vessels of different shapes.
d. For sterilisation purposes.
e. Can be used in the ice industry.
f. Can be collected in various water reservoirs.
g. Can make puttu using steam.
h. For preparing soda water.
Answer:
a. Dissolves substances.
b. Flows.
c. Has no definite shape, takes the shapes of the container.
d. carries heat.
e. Exists in solid, liquid and gaseous states.
f. Has no definite shape, take the shape of the container.
g. Exists in solid, liquid and gaseous state.
h. Dissolves substances.

Question 22.
A) Complete the table suitably related to dissolving property.

Solute	a)	b)
c)	Water	Soda water
Sugar	Water	d)
e)	0	Copper sulphate solution

B) Three statements related to water are given below. Pick out the correct statements from them.

• The major portion of water present on the Earth is pure.
• Water is called the universal solvent due to its dissolving property.
• Water vapour ¡s the gaseous state of water.

Answer:
A)
a) Solvent
b) Solution
e) Carbon dioxide
d) Sugar solution
e) Copper sulphate
f) Water

B)

• Water is called the universal solvent due to its dissolving property.
• Water vapour is the gaseous state of water.

Question 23.
Observe the picture

a) Which property of water is picturised?
b) What changes in the water level can be seen if we put some sand in the middle vessel?
c) How is the water level in the nearby wells affected if sand ¡s mined from rivers?
Answer:
a) Water maintains its level.
b) Water level increases in the three vessels and thus water maintains its level.
e) If sand is mined from rivers water level in the nearby wells decreases.

Question 24.
Notice the following statement.
(The property of water to dissolve substances helps in washing clothes)
A. List any other two properties of water and write two daily life situations where these properties are used.
B. Complete the table

(i) ……………………..	(ii)……………………….	Solution
Sugar	(iii)……………………	Sugar solution
(iv)……………….	Water	Soda water
(v)…………..	Water	(vi)…………..

Answer:
A.

Properties of water	Situations used
Has no definite shape; takes the shape of the container	Can be collected in containers of different shapes
Exists in solid, liquid and gaseous state	Can be used in ice industry

B.

Properties of water	Situations used
Has no definite shape; takes the shape of the container	Can be collected in containers of different shapes
Exists in solid, liquid and gaseous state	Can be used in ice industry

Water and Life Class 6 Notes

All animals and plants need water to survive. Those who live on “dry” land get their water from the soil or from streams, rivers, lakes, puddles, dew or raindrops. Water is also vital for our own lives. We collect and store water for drinking and washing, for our pets and farm animals, and for irrigating our crops. Each person needs to take in atleast two litres of water daily, to stay alive and healthy. Wells, Tubewells, Rainwater, Lakes, Ponds, Streams etc are the main sources of water. The availability of fresh water is decreasing due to an increase in population and an increase in the level of water pollution.

Properties Of Water

• Water has no definite shape. So it takes the shape of the container in which it ¡s filled.
• Some objects, like coins and stones, sink in water whereas some other objects like paper boats and ice, float on water.
• Some substances like salt and vinegar are soluble in water whereas some other substances like kerosene and wax are insoluble in water.
• A solution is formed when the solute is dissolved in the solvent.
  Solute + Solvent —Solution
• Water has the ability to dissolve many substances. Hence water is called the universal solvent.
• The speed of dissolution of substances depends on the following factors:
  1. Powdered substances have a greater speed of solubility
  2. On strong stirring, the speed of solubility increases
  3. On getting hotter, the speed of solubility increases
• Water can exist in all three states of matter.
  Solid — ice, Liquid — water, Gas — water vapour
• The spreading of small particles of liquid from its surface to the surroundings is called vapourisation. As the substance heats up, the rate of vapourisation increases. Vapourisation occurs at all temperatures.
• Water maintains its level. This is a property of water. Builders fill a tube with water and place it between two points. If the water in the tube is at the same height as the reference point, then the two points are at the same level.

Water Sources

• Earth is a watery planet.
• As the water bodies get heated up, water rises into the atmosphere. Then the water gets cooled and turns into rain clouds.
• Then small particles in the rain clouds combine together.as raindrops and fall to earth as rain.
  Water pollution occurs when harmful substances contaminate water, making it unsafe for plants, animals, and people.

Causes of water pollution

• Washing of clothes and vehicles in rivers.
• Dumping domestic waste into the rivers.
• Dumping factory waste into the rivers.
• Giving cattles a bath in the rivers.
• Flow of fertilisers and pesticides from agricultural fields to the rivers.
• Dumping of human excreta into the rivers.

Remedies

• Avoid washing of clothes and vehicles in rivers.
• Avoid giving cattles a bath in the rivers.
• Adopt suitable methods for waste disposal in houses.
• Avoid dumping factory waste into the rivers.
• Use fertilisers and pesticides wisely.
• Use toilets and other sanitation facilities.
• The methods used for water storage include rainwater storage tanks, check dams, stone walls,well recharging,water fences, etc
• Pure water is precious. We should conserve it for our future.