Fresh air, fertile soil, abundant sunlight — a village near the Western Ghats has plenty to remind us what nature freely gives.
Key idea
Air
1
Air is a mixture of gases
mostly nitrogen (78%) and oxygen (21%), with argon, carbon dioxide, and other gases making up the rest.
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2
Our need for oxygen
We can survive days without food or water, but only minutes without oxygen.
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3
Wind energy
Moving air is wind — gentle as a breeze or strong as a storm. Windmill farms harness it to generate electricity.
Key idea
Water
1
Everywhere, but...
Water covers about two-thirds of Earth, but most (in oceans) is saline and unusable directly.
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2
Conserving it
Rainwater harvesting and traditional stepwells (Bawadi, Vav) store water for later use.
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3
Pollution
Dumping waste into water sources makes water unfit for use — protecting water means keeping it clean.
Key idea
Energy from the Sun
The Sun is the main source of energy on Earth. Plants make their own food using sunlight — energy then passes from the Sun to plants to animals.
Using solar energy directly
Solar cookers for cooking, solar water heaters for hot water, and solar panels for generating electricity.
Key idea
Forests
1
Shelter and food
Dense plant growth gives food and shelter to wild animals, birds, and insects.
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2
The Chipko movement
In the early 1970s, women in Uttarakhand hugged trees to stop them from being felled.
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Van Mahotsav
A week-long tree-planting festival held every July to raise awareness of forest conservation.
Key idea
Soil, Rocks, and Minerals
1
Soil
Formed when rocks slowly break apart, over thousands of years, through the action of the Sun, water, and living organisms like earthworms.
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Rocks and minerals
Rocks like granite, sandstone, marble, and laterite are used for construction. Metals such as aluminium, gold, copper, and iron are extracted from minerals.
Key idea
Fossil Fuels
Petroleum, natural gas, and coal are together called fossil fuels — formed from the remains of ancient microorganisms and plants buried underground.
Fossil fuel | Common use
PetroleumPetrol, diesel, kerosene
Natural gasCooking, CNG for vehicles
CoalGenerating electricity
Key idea
Renewable and Non-renewable Resources
1
Renewable resources
Get replenished naturally within a reasonable time — air, water, forests.
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2
Non-renewable resources
Take millions of years to form and are limited — coal, petroleum, natural gas, minerals, rocks.
Chapter · Key terms to remember
Key Terms
Natural resources
Things we get from nature.
Human-made resources
Things people create from natural resources.
Renewable resources
Replenished naturally, e.g. air, water, forests.
Chapter · Key terms to remember
More Key Terms
Non-renewable resources
Limited, take ages to form.
Fossil fuels
Coal, petroleum, natural gas.
Rainwater harvesting
Collecting and storing rainwater.
Chapter · Key terms to remember
More Key Terms
Soil
Formed from broken-down rock over time.
Minerals
Substances in rocks that metals are extracted from.
Questions for your notebook
Write these down, then discuss
1
Unjumble ocrk, refost, ndiw, atwre — name these resources and classify each as renewable or non-renewable.
2
True or False, correcting the false ones: (i) Nature has all the resources to meet human needs. (ii) Machines are a resource found in nature. (iii) Natural gas is a non-renewable resource. (iv) Air is a renewable resource.
3
Fill in the blanks: (i) A fuel commonly used in two-wheelers is (a) Kerosene (b) Petrol (c) Diesel (d) LPG. (ii) An example of a renewable resource is (a) Coal (b) Water (c) Natural gas (d) Petrol.
Project as-is — students copy the questions, then the class discusses answers together.