Chapter 5: Coal and Petroleum
1. Natural Resources
• Natural resources: Materials provided by nature used by humans.
• Two types:
• Inexhaustible: Unlimited (e.g., air, water, sunlight).
• Exhaustible: Limited in quantity; can be exhausted (e.g., coal, petroleum, natural gas).
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2. Fossil Fuels
• Coal, petroleum, and natural gas are called fossil fuels.
• Formed from the dead remains of plants and animals buried millions of years ago under heat and pressure.
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3. Coal
• A black, hard substance used as a fuel.
• Mainly carbon.
• Formed from dead vegetation (plants) → converted into peat → then coal over millions of years.
• This process is called carbonization.
• Used in: cooking, industries, electricity generation (thermal power plants), and steam engines.
Coal Products
1. Coke – Tough, porous; used in steel and extraction of metals.
2. Coal tar – Thick black liquid; used to make dyes, drugs, explosives, paints.
3. Coal gas – Used as fuel in industries.
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4. Petroleum
• Formed from dead aquatic animals and plants.
• Found between layers of rocks under the earth’s crust.
• Extracted through oil wells.
• Petroleum is refined in oil refineries to separate useful products.
Petroleum Products (from refining)
|
Product |
Uses |
|
Petrol |
Vehicles (cars, bikes) |
|
Diesel |
Trucks, buses, generators |
|
Kerosene |
Cooking and lighting |
|
Lubricating oil |
Lubrication |
|
Paraffin wax |
Candles, ointments, vaseline |
|
Bitumen |
Road surfacing |
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5. Natural Gas
• Found along with petroleum.
• Clean fuel, used in homes and vehicles (CNG – Compressed Natural Gas).
• Also used in power generation and as raw material in industries.
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6. Conservation of Fossil Fuels
• Fossil fuels are exhaustible and take millions of years to form.
• To save fuel:
• Use public transport.
• Switch off vehicles at red lights.
• Use bicycles for short distances.
• Use renewable energy sources (solar, wind, etc.).
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Important Definitions
• Exhaustible Resources: Limited in quantity (coal, petroleum).
• Inexhaustible Resources: Unlimited in nature (sunlight, air).
• Carbonization: Process of conversion of dead vegetation into coal.
• CNG: Compressed Natural Gas – clean and environment-friendly fuel.
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Short Questions for Practice
1. What are fossil fuels?
2. How is petroleum formed?
3. What are the uses of coke?
4. Name two products obtained from petroleum.
5. What is the need for conserving fossil fuels?