1/62
What is the most important natural resource given by nature?
Water.
2/62
What are some common sources of water mentioned in the environment?
Rivers, streams, ponds, wells.
3/62
Why do we commonly think of water in liquid form?
Because water is most commonly found in the liquid state in our environment.
4/62
What are the three physical states of water?
Solid (ice), Liquid (water), Gas (water vapour).
5/62
What happens when ice cubes are heated in a test tube?
Ice melts into liquid water; further heating turns it into water vapour.
6/62
In Activity 3.1, what tool is used to hold the test tube while heating?
A test tube holder.
7/62
What state of water is represented by water vapour?
Gas.
8/62
What is the physical state of ice?
Solid.
9/62
What is the physical state of liquid water?
Liquid.
10/62
What does the observation in Activity 3.1 prove about water?
That water can exist in all three states — solid, liquid, and gas.
11/62
What are the three states of water in nature?
Solid, liquid, and gas.
12/62
Give three examples of water in its solid state.
Ice, snow, glaciers.
13/62
Why can snow and glaciers be considered solid states of water?
Because they have a fixed shape and volume, characteristic of solids.
14/62
Where can glaciers be commonly found?
In the Northern and Southern Poles of the world.
15/62
Name five places where liquid water can be seen in nature.
Rivers, lakes, ponds, wells, seas.
16/62
Why is liquid water the most familiar form of water to us?
Because we commonly encounter it in lakes, rivers, and during daily use.
17/62
What are two examples of the gaseous state of water?
Steam and water vapour.
18/62
Where does water exist as vapour in nature?
In the atmosphere.
19/62
In Activity 3.2, what happens to the outer surface of the glass after ice cubes are added and it is closed with cardboard?
Water droplets form due to condensation of water vapour from the air.
20/62
What conclusion can you make from Activity 3.2?
Water vapour is present in the atmosphere and condenses on cool surfaces.
21/62
What are the three main types of water based on availability?
Precipitation, surface water, and ground water.
22/62
What is precipitation?
Water that falls from the atmosphere to Earth, such as rain, snow, hail, or sleet.
23/62
List four examples of precipitation.
Rain, snow, hail, sleet.
24/62
What is surface water?
Water that collects or flows on the Earth's surface such as in rivers, lakes, or ponds.
25/62
Give five examples of surface water.
Rivers, ponds, lakes, seas, waterfalls.
26/62
What is ground water?
Water found below the surface of the Earth, stored in soil or rock layers.
27/62
Name two examples of ground water sources.
Wells and springs.
28/62
In Activity 3.3, why are materials like sand, gravel, and clay used in the glass tank experiment?
To simulate different layers of soil and observe how water behaves (flows, absorbs, or pools).
29/62
What does water that flows through the soil layers in Activity 3.3 represent?
Ground water.
30/62
What does water that remains on top of the soil represent in the activity?
Surface water.
31/62
Why does seawater taste salty?
Because it contains dissolved salts, mainly sodium chloride.
32/62
What property of water allows it to dissolve many substances?
Water's polarity — it is called the universal solvent.
33/62
Name the three types of water based on salinity.
Fresh water, marine water, and brackish water.
34/62
Give examples of fresh water sources.
Rivers, ponds, wells, streams, waterfalls.
35/62
What is marine water?
Water from seas and oceans with a high amount of dissolved salts.
36/62
Where is brackish water commonly found?
In lagoons.
37/62
How does brackish water compare to fresh and marine water in salinity?
It has more salt than fresh water but less than marine water.
38/62
What is the source of salt production in coastal regions?
Salt (sodium chloride) is produced in salterns by evaporating seawater.
39/62
In Activity 3.4, which sample has the highest mass: fresh water, 2g salt water, or 6g salt water (all 25 ml)?
The 6g salt water sample, because dissolved salt increases the mass.
40/62
What conclusion can be made from Activity 3.4 about water salinity and mass?
The greater the amount of dissolved salt in a fixed volume, the higher the mass — allowing identification of fresh, brackish, and marine water.
41/62
How can you compare a sample of marine water and fresh water using mass?
By measuring equal volumes of both and weighing them — the marine water will have more mass due to higher salt content.
42/62
Name three basic household uses of water.
To drink, to wash clothes, to bathe.
43/62
How is water used in agriculture?
For irrigating crops and supporting plant growth.
44/62
How is water used in generating electricity?
Water is used in hydroelectric power plants to produce electricity.
45/62
Give two examples of how water is used in transportation.
Boats and ships travel on rivers and seas.
46/62
What are the seven categories of water use?
For industries including agriculture
For sanitary purposes
For household activities
For transportation
For leisure
For water-related sports
To generate electricity
For sanitary purposes
For household activities
For transportation
For leisure
For water-related sports
To generate electricity
47/62
How does water help animals in digestion and excretion?
It helps digest food and acts as a medium for excreting waste.
48/62
Why is dehydration dangerous to humans?
It causes a loss of water in the body, which can lead to weakness or death if untreated.
49/62
Name three roles of water in plants.
For photosynthesis
To absorb minerals
To maintain rigidity
To absorb minerals
To maintain rigidity
50/62
Why is water essential for transporting nutrients in the body?
It acts as a fluid medium to carry nutrients through blood and other body fluids.
51/62
A plant is withered and drooping. What is the likely cause, and how is water involved?
The plant likely lacks water, which is needed for rigidity and mineral absorption.
52/62
Why is water considered a limited natural resource even though it covers over 70% of the Earth?
Because only about 0.01% of it is suitable for human consumption.
53/62
What percentage of water is found in solid form?
2.58%.
54/62
What percentage of water is found in seas and oceans?
97.41%.
55/62
Give one reason why most available water sources are not directly usable.
Because they are either too salty, frozen, or polluted.
56/62
List one occasion of water waste at home and how it can be reduced.
Leaving the tap running while brushing teeth → Turn off the tap when not in use.
57/62
What is water pollution?
The addition of harmful waste to water until it becomes unsuitable for consumption.
58/62
Name three human activities that cause water pollution.
Releasing chemicals from factories, washing/bathing in water bodies, dumping plastic waste.
59/62
How does surface water pollution affect ground water?
Poisonous chemicals from surface water seep into ground water, contaminating drinking sources.
60/62
What can be the consequences of drinking polluted water?
Serious illnesses such as cancer and kidney failure.
61/62
What should we do to protect our limited supply of clean water?
Avoid polluting water sources and take steps to conserve water.
62/62
Summarize five key facts about water discussed in this chapter.
Water is essential for life
Exists in solid, liquid, and gas forms
Categorized by availability (precipitation, surface, ground)
Classified by salinity (fresh, marine, brackish)
Polluted water reduces usable supply
Exists in solid, liquid, and gas forms
Categorized by availability (precipitation, surface, ground)
Classified by salinity (fresh, marine, brackish)
Polluted water reduces usable supply
.png)
.png)
