Class 8 Science – Coal and Petroleum: Fossil Fuels

1. Introduction

• Fossil fuels are non-renewable energy sources formed from the remains of ancient plants and animals over millions of years.

• Main fossil fuels: Coal, Petroleum (Crude Oil), and Natural Gas.

• They provide energy for domestic, industrial, and transportation purposes.

Key Concept:

• Fossil fuels are stored energy from the past and take millions of years to form.

2. Coal

• Coal is a solid fossil fuel formed from plant remains.

• Found in coal mines and extracted through mining.

• Types of coal: Vary based on carbon content (from brown coal to hard coal).

Uses of Coal

1. Fuel: Used in steam engines, electricity generation, and industries.

2. Manufacturing: Used in making coke for steel production.

3. Domestic: Used for cooking and heating in rural areas.

Key Concept:

• Coal is carbon-rich and releases a lot of energy when burned.

3. Petroleum (Crude Oil)

• Petroleum is a liquid fossil fuel formed from marine organisms buried under layers of sediment.

• Extracted through oil drilling from oil wells.

• Petroleum is refined into useful products.

Products and Uses of Petroleum

1. Petrol and Diesel: Fuel for vehicles and transportation.

2. Kerosene: Fuel for lamps, heaters, and cooking stoves.

3. Lubricants: Reduce friction in machines.

4. Plastics and Polymers: Raw material for plastic products.

5. Other products: Asphalt for roads, chemicals, and synthetic materials.

Key Concept:

• Petroleum is versatile because it can be refined into many products.

4. Advantages of Fossil Fuels

• High energy content → efficient for heating and electricity.

• Easily transportable and storable.

• Widely available and used in industrial, domestic, and transportation sectors.

5. Disadvantages of Fossil Fuels

• Non-renewable: Take millions of years to form → limited supply.

• Pollution: Burning releases smoke, carbon dioxide, and harmful gases.

• Environmental Impact: Mining and drilling can destroy habitats and cause oil spills.

• Contributes to global warming and climate change.

6. Key Points to Remember

• Fossil fuels are formed from ancient plants and animals over millions of years.

• Coal → solid fuel from plant remains; Petroleum → liquid fuel from marine organisms.

• Both are high-energy sources widely used in daily life.

• Advantages: High energy, easily used and transported.

• Disadvantages: Non-renewable, polluting, environmentally harmful.

• Sustainable alternatives like solar, wind, and hydro energy are important for the future.