Chapter 11: Nature’s Treasures

1. Nature’s Treasures

Nature provides everything essential for life, such as:

Air
Water
Sunlight
Forests
Soil
Rocks and minerals
Fossil fuels

All living beings depend on these natural resources for survival. Therefore, they should be used carefully and responsibly.

2. Air

Air is a mixture of gases.
Main components of air:
- Nitrogen – 78%
- Oxygen – 21%
- Argon, carbon dioxide and other gases – 1%
Oxygen is essential for the survival of most living beings.
Moving air is called wind.
Wind may be gentle like a breeze or strong like a storm.
Wind energy can be used in windmills to:
- Generate electricity
- Pump water
- Run flour mills

3. Water

Water is essential for:

Drinking
Cooking
Bathing
Washing and cleaning
Growing crops
Industries

Freshwater and Saline Water

About two-thirds of Earth's surface is covered by water.
Most water is in oceans and seas and is saline (salty).
Freshwater is found in:
- Rivers and lakes
- Ponds and wells
- Ice sheets and snow
- Underground

Only a small amount of freshwater is easily accessible.

Water Conservation

We can save water by:

Turning off taps when not needed.
Repairing leaking taps and pipes.
Reusing/recycling water.
Using water carefully while gardening, washing and cleaning.
Practising rainwater harvesting.

4. Water Pollution

Water becomes polluted when harmful waste is added to water sources.

Major causes

Household waste
Industrial waste
Plastic bags and wrappers
Dumping garbage into rivers, lakes and ponds

Polluted water is not fit for consumption by living beings.

Freshwater is limited, so we must both conserve water and prevent its pollution.

Rainwater Harvesting

Rainwater harvesting means collecting and storing rainwater for later use.

Traditional Indian examples include:

Bawadi – Rajasthan
Vav – Gujarat

5. Energy from the Sun

The Sun is the main source of energy on Earth.

Sunlight provides:

Heat
Light
Energy needed by plants to make food

Plants use sunlight to prepare food. Animals depend directly or indirectly on plants, so all living beings ultimately depend on the Sun for energy.

Uses of Solar Energy

Drying clothes and food
Solar cooking
Heating water
Generating electricity using solar panels

6. Forests

A forest is a large area with dense growth of different types of plants.

Importance of Forests

Forests:

Provide food and shelter to animals, birds and insects.
Provide many useful products.
Support biodiversity.
Help protect soil.
Maintain ecological balance.

Forest Conservation

Forest cover is decreasing mainly because of activities such as large-scale cutting of trees.

We should:

Protect forests.
Avoid unnecessary cutting of trees.
Plant more trees.
Use forest resources responsibly.

Van Mahotsav

Van Mahotsav is a week-long forest festival celebrated in July. It promotes tree plantation and awareness about protecting forests.

Chipko Movement

The Chipko Movement began in the early 1970s in Uttarakhand. Local people, especially women, hugged trees to protect them from being cut down.

7. Soil

Soil supports plant growth and biodiversity.

Importance of Soil

Provides support and nutrients to plants.
Contains air spaces for roots.
Provides a habitat for organisms.
Supports agriculture.

Earthworms help turn and loosen soil.

Formation of Soil

Soil forms over a very long period when rocks break down due to the action of:

Sun
Water
Living organisms

This process takes thousands of years.

Recycling in Nature

Fallen leaves and dead organisms decay and add nutrients to soil. These nutrients are then used by new plants.

8. Rocks and Minerals

Rocks

Rocks are useful for:

Construction of houses and buildings
Roads and dams
Roofing
Making tools

Examples:

Granite
Sandstone
Marble
Slate
Laterite

Rocks take thousands to millions of years to form, so they should be conserved.

Minerals

Rocks are made up of minerals.

Important metals obtained from minerals include:

Iron
Copper
Aluminium
Gold

Minerals are used in:

Vehicles
Aircraft
Jewellery
Cosmetics
Electrical and electronic equipment

9. Fossil Fuels

Fossil fuels are fuels formed from the remains of microorganisms and plants buried deep inside Earth over millions of years.

Main Fossil Fuels

Coal
Petroleum
Natural gas

Uses

Petrol and diesel are widely used in vehicles.
Natural gas is used for cooking and electricity generation.
CNG is used as a vehicle fuel and is cleaner than petrol or diesel.
Coal is mainly used to produce electricity.

Problems with Fossil Fuels

They are available in limited quantities.
They take millions of years to form.
Burning them releases smoke and carbon dioxide.
Excessive use causes air pollution.

10. Natural Resources

Resources obtained from nature are called natural resources.

Examples:

Air
Water
Sun
Forests
Soil
Rocks
Minerals
Fossil fuels

Resources created by humans, such as furniture, bicycles and electric bulbs, are called human-made resources. Chapter 11

11. Renewable and Non-Renewable Resources

Renewable Resources	Non-Renewable Resources
Can be renewed naturally	Cannot be replenished in a reasonable period
Available through natural processes	Available in limited quantities
Examples: air, water, forests	Examples: coal, petroleum, natural gas
Can be restored if used wisely	Once exhausted, they take a very long time to form

Key Difference

Renewable resources → nature can replenish them within a reasonable period.

Non-renewable resources → nature cannot replenish them within a reasonable period.

12. Conservation of Natural Resources

We should conserve natural resources because they are essential for present and future generations.

We can:

Save water.
Harvest rainwater.
Plant and protect trees.
Reduce air pollution.
Walk or cycle for short distances.
Use public transport.
Reduce unnecessary use of fossil fuels.
Avoid wasting natural resources.
Reuse and recycle materials.
Protect forests, soil and water bodies.

The chapter emphasizes that natural resources should be used judiciously, without harming the environment.

Important Terms to Remember

Natural resources: Resources obtained from nature.

Human-made resources: Resources created by humans.

Renewable resources: Resources that are naturally renewed or replenished within a reasonable period.

Non-renewable resources: Resources available in limited quantities that cannot be replenished within a reasonable period.

Fossil fuels: Coal, petroleum and natural gas formed over millions of years.

Rainwater harvesting: Collecting and storing rainwater for later use.

Wind: Moving air.

Water pollution: Contamination of water by harmful substances.

Minerals: Naturally occurring materials from which useful metals and other substances are obtained.

Van Mahotsav: A forest festival held in July to promote tree plantation and forest conservation.

Chipko Movement: A movement in which people, especially local women, protected trees from being cut by hugging them.

Answers to Chapter Questions

1. Match the jumbled names and classify the resources

Jumbled Name	Correct Name	Type
ocrk	Rock	Non-renewable
refost	Forest	Renewable
ndiw	Wind	Renewable
atwre	Water	Renewable

Classification:

Renewable: Forest, Wind, Water
Non-renewable: Rock

2. True or False

(i) Nature has all the resources to meet human needs.
True [T]

(ii) Machines are a resource found in nature.
False [F]
Correction: Machines are human-made resources.

(iii) Natural gas is a non-renewable resource.
True [T]

(iv) Air is a renewable resource.
True [T]

3. Fill in the blanks

(i) A fuel commonly used in two-wheelers like scooters and bikes is (b) Petrol.

(ii) An example of a renewable resource is (b) Water.

4. Classify the resources

Resource	Type
Coal	Non-renewable
Natural gas	Non-renewable
Forests	Renewable
Minerals	Non-renewable

Fossil fuels and minerals occur in limited quantities and are not replenished within a reasonable period. Forests can regenerate naturally, though they must be used responsibly.

5. Why is petroleum a non-renewable resource?

Petroleum is a non-renewable resource because it takes millions of years to form from the remains of organisms buried deep inside the Earth. It is available in limited quantities and cannot be replenished within a reasonable period after use.

6. Why is it difficult to regrow forests?

It is difficult to regrow forests because trees take many years to grow. A forest is a complex ecosystem containing many plants, animals and other organisms. Therefore, restoring a lost forest takes a long time.

7. Five daily activities using natural resources and ways to reduce their use

Daily Activity	Natural Resource	Way to Reduce Use
Brushing teeth	Water	Turn off the tap while brushing
Bathing	Water	Use water carefully
Cooking	Water, fuel	Avoid wastage of water and fuel
Travelling	Fossil fuels	Walk, cycle or use public transport
Making/cooking food	Plants, animals, water, fuel	Avoid wasting food and resources

We should use natural resources carefully and avoid unnecessary wastage.

8. Four activities possible due to air

Four activities are:

Breathing
Flying kites
Sailing boats
Generating electricity using windmills

Moving air is called wind, and its energy can be used in several ways.

9. How can you enhance the green cover of your locality?

We can:

Plant more trees.
Take care of newly planted trees.
Organise tree-plantation drives.
Protect existing trees from unnecessary cutting.
Encourage people to protect forests and plants.
Maintain green areas in schools and neighbourhoods.

Van Mahotsav is one example of an activity that promotes tree plantation and awareness about forests.

10. Energy used for cooking

(i) The type of energy depends on the cooking method shown. If the illustration represents a gas stove, then chemical energy of the fuel is converted mainly into heat energy.

(ii)
Benefit: It provides useful heat for cooking food.
Drawback: Burning fuel can produce pollutants and contribute to air pollution.

The chapter explains that burning fossil fuels produces smoke and carbon dioxide and contributes to air pollution.

11. How does cutting trees affect soil quality?

Trees help protect soil because their roots hold the soil together and prevent it from being washed away. When trees are cut on a large scale, soil becomes more vulnerable to erosion. Also, fewer fallen leaves are available to decay and add nutrients to the soil.

12. How do human activities pollute air?

Two ways are:

Burning fossil fuels in vehicles releases smoke and carbon dioxide.
Excessive use of fossil fuels as domestic and transportation fuels increases air pollution.

One action: Use public transport, walking or cycling instead of using private vehicles for short distances.

13. What happens if there is no sunlight for a week?

Solar panels would not receive sunlight and would not generate solar energy normally.
Plants would not receive sunlight for photosynthesis.
The solar water heater would not receive solar heat.
The windmill could still work if there is sufficient wind because wind energy does not directly depend on sunlight for its operation.
The gas stove could still work if there is a supply of gas.

Thus, the absence of sunlight would particularly affect systems that directly depend on solar energy.

14. Fill in the blanks

The question provides these terms:

fossil fuels, forest, air, petroleum, coal, water, non-renewable resource

The exact blanks/illustration for this exercise are not visible in the supplied text extraction, so the individual answers cannot be matched reliably without inventing the missing sentences.

15. Is cutting trees for industries and housing justified?

Large-scale cutting of trees is not justified when it causes unnecessary destruction of forests.

Forests provide food and shelter for animals, support biodiversity and help protect soil. Trees also take many years to grow. Therefore, development should be planned carefully, unnecessary cutting should be avoided, and tree plantation and forest conservation should be promoted.

Conclusion: We should meet human needs while protecting forests for future generations.

16. Plan to use less water in school

Plan:

Check all taps and repair leakages.
Turn off taps immediately after use.
Put reminders near washbasins.
Use water carefully while cleaning classrooms.
Avoid unnecessary use of water in gardens.
Reuse suitable water wherever possible.
Collect rainwater through rainwater harvesting.
Conduct awareness activities for students.

Benefits:

Saves precious freshwater.
Reduces water wastage.
Helps conserve natural resources.
Encourages students to develop responsible habits.
Supports environmental conservation.