11.1 Air around Us
We can survive without food or water for days, but cannot survive without oxygen for even a few minutes!
Composition of Air (10x10 Grid)
Nitrogen: 78%
Oxygen: 21%
Argon, CO2, others: 1%
Note: Moving air is called wind. We can see its presence when leaves rustle or paper pinwheels (firki) rotate!
Wind Power
Windmills operate on the same principle as a paper firki. They are used to:
- Run flour mills
- Pump underground water
- Generate clean electricity
Leading Wind Farms in India:
- • Muppandal Wind Farm - Tamil Nadu
- • Jaisalmer Wind Park - Rajasthan
- • Brahmanvel Wind Farm - Maharashtra
11.2 Water Wisdom
~2/3 of Earth is covered by water!
🌊 Saline Water: Found in oceans & seas. Unfit for domestic, industrial, or farming use.
❄️ Freshwater: Locked in ice sheets, snow, rivers, lakes, and underground. Extremely precious!
Rainwater Harvesting (RWH)
Traditional methods collect rainwater directly to combat scarcity:
(Rajasthan)
(Gujarat)
World Water Day: 22nd March
11.3 Solar Energy
The Sun is the ultimate source of energy on Earth. All plants and animals depend directly or indirectly on it.
How is Solar Energy Captured?
- ☀️ Direct Heat: Solar cookers, drying clothes & crops (e.g., chillies, mangoes).
- ⚡ Solar Panels: Capture sunlight & convert it into electricity for households, street lights, and traffic signals.
11.4 Forests & Nature
Forests are large areas with dense growth of plants providing food and shelter to wildlife.
Van Mahotsav
A week-long tree plantation festival celebrated across India in July.
Chipko Movement
Started in the early 1970s in Uttarakhand. Brave local women hugged trees to prevent them from being felled!
Traditions forbid plucking certain fruits; they are left entirely for forest animals and birds!
11.5 Soil & Rocks
Soil Formation: Formed by the disintegration (breaking apart) of rocks via the actions of the Sun, water, wind, and organisms over thousands of years!
Earthworms are natural tillers!
They help loosen the soil, creating air spaces for plant roots to grow smoothly.
Rocks Used
Slate (roofing), laterite (bricks), granite, sandstone, marble (sculptures/construction).
Minerals Extracted
Aluminium, Gold, Copper, Iron, Silver, Cobalt (vital for mobile phones!).
11.6 Fossil Fuels
Formed from the remains of microorganisms and plants buried deep inside the Earth over millions of years.
11.7 Natural Resources
Renewable
Get renewed or restored by natural processes within a short span of time.
☀️ Air, Water, Forest
Non-Renewable
Exist in limited quantities and take millions of years to form.
🛢️ Coal, Petrol, Minerals
Nature's Golden Rule
"Earth provides enough to satisfy every man's need but not for every man's greed."
- M. K. Gandhi