All questions of Energy Resources for Grade 6 Exam

The process of conversion of dead plants material into coal is called carbonization.

Coal may be classified in rock types (or lithotypes) based on the presence of petrological components known as macerals. Based on maceral content and its appearance in a hand specimen, coal is classified into four principal types: clarain, durain, fusain, and vitrain.

Paraffin wax is not obtained from coal tar; it is a constituent of petroleum. Coal tar produces substances like synthetic dyes, perfumes, and naphthalene balls.

The word petroleum is derived from the words "petra" (rock) and "oleum" (oil), thus commonly known as rock oil.

Understanding Natural Gas Storage
Natural gas is a vital energy source used for heating, electricity generation, and as fuel for vehicles. Its storage is crucial for managing supply and demand.
What is Compressed Natural Gas (CNG)?
- CNG stands for Compressed Natural Gas.
- It is natural gas that has been compressed to less than 1% of its volume at standard atmospheric pressure.
- CNG is stored in high-pressure containers, making it efficient for storage and transportation.
Why is CNG Used for Storage?
- Safety: CNG is non-toxic and produces fewer emissions compared to other fossil fuels.
- Efficiency: Compressing natural gas allows for easy transport and storage, especially in areas without pipeline access.
- Versatility: CNG can be used in various applications, including vehicles, industrial processes, and residential heating.
Comparison with Other Fuels
- Coal: A solid fossil fuel, coal is not stored under pressure and is used primarily for electricity generation.
- Diesel: A liquid fuel derived from crude oil, diesel is stored in tanks but does not involve compression like CNG.
- Petrol: Also a liquid fossil fuel, petrol is used mainly in internal combustion engines and is stored in liquid form.
Conclusion
Compressed Natural Gas (CNG) is the preferred method for storing natural gas under high pressure due to its safety, efficiency, and versatility. Understanding these differences helps in appreciating the role of CNG in our energy systems.

What are Fossil Fuels Made From?
Fossil fuels are a vital energy source and are primarily formed from the remains of living organisms. Understanding this process helps us appreciate how these fuels are created over millions of years.
Formation Process
- Fossil fuels are formed from the remains of ancient plants and animals, primarily:
- Plants: These include trees, ferns, and other vegetation.
- Animals: Marine creatures like plankton and fish also contribute.
- The process of formation involves several key stages:
- Sedimentation: When these organisms die, they settle in layers on the ocean or land floor, where they become buried by sediments.
- Heat and Pressure: Over millions of years, heat and pressure transform these organic materials into fossil fuels, which can be:
- Coal: Formed from plant remains in swampy areas.
- Oil: Created from marine organisms in ocean basins.
- Natural Gas: Often found alongside oil or in shale deposits, derived from both plants and animals.
Importance of Fossil Fuels
- Fossil fuels are crucial for:
- Energy Production: Used for electricity generation, heating, and powering vehicles.
- Industrial Uses: Serve as raw materials in manufacturing products like plastics and chemicals.
Environmental Considerations
- While fossil fuels are essential, their extraction and use can lead to environmental concerns, such as pollution and climate change.
In summary, fossil fuels are primarily made from the remains of living organisms that have undergone a complex geological process over millions of years, highlighting the intricate relationship between life and energy on our planet.

Petroleum gas in liquid form (LPG) is primarily used as fuel for homes and industries.

Coke, an almost pure form of carbon obtained from coal, is used in the manufacture of steel.

Understanding Coal Composition
Coal is a sedimentary rock that primarily consists of carbon. Its formation occurs over millions of years from the remains of ancient plants and trees, which undergo a process of heat and pressure. Let’s delve into the key components:
Main Component: Carbon
- Carbon Content: Coal typically contains about 50% to 90% carbon. This high carbon content is what makes coal a potent fuel source, providing energy when burned.
- Energy Production: The carbon in coal reacts with oxygen during combustion, releasing energy in the form of heat. This heat is used for electricity generation, heating, and industrial processes.
Other Components
- Hydrogen: Although present in coal, hydrogen constitutes a smaller percentage compared to carbon. It usually ranges from 3% to 6%.
- Oxygen: Coal also contains oxygen, typically making up about 1% to 10% of its composition. However, it is still significantly less than the carbon content.
- Nitrogen and Sulfur: Coal may contain trace amounts of nitrogen and sulfur, which can contribute to environmental issues such as air pollution when coal is burned.
Conclusion
In summary, while coal does contain other elements like hydrogen, oxygen, nitrogen, and sulfur, its primary and most significant component is carbon. This characteristic is what makes coal an essential fuel source for energy production worldwide.

When coal is heated in air, it burns and produces mainly carbon dioxide gas.

Coke is a tough, porous, and black substance that is almost a pure form of carbon. It is used in the manufacture of steel and in the extraction of many metals.

Kerosene is used as a fuel for jet aircrafts as well as for stoves and lamps.

Paraffin wax, obtained from petroleum, is primarily used for making candles, ointments, and vaseline.

CNG stands for Compressed Natural Gas, which is natural gas stored under high pressure.

- CNG, or Compressed Natural Gas, is a cleaner-burning fuel compared to coal, diesel, and petrol.
- It produces fewer harmful emissions, such as nitrogen oxides and particulate matter, which contribute to air pollution.
- CNG is primarily methane, which burns more efficiently and generates less carbon dioxide than other fossil fuels.
- Many transport vehicles, like buses and taxis, are increasingly using CNG to reduce their environmental impact.
- Overall, CNG is a more sustainable option for transportation.

Answer:

Introduction:
The petroleum product used for surfacing roads is called bitumen. Bitumen is a thick, black, viscous liquid or semi-solid form of petroleum. It is primarily used in road construction and maintenance due to its excellent adhesive and waterproofing properties.

Explanation:
Bitumen is derived from the fractional distillation of crude oil. During the refining process, bitumen is obtained when the heaviest components of crude oil are separated from the lighter fractions. It is composed mainly of hydrocarbons, which are organic compounds composed of hydrogen and carbon atoms.

Properties of Bitumen:
Bitumen possesses several properties that make it suitable for surfacing roads:

1. Adhesion: Bitumen has excellent adhesive properties, allowing it to bind aggregates together. This property helps to create a strong and durable road surface.

2. Waterproofing: Bitumen is highly impermeable to water, preventing water from seeping into the road structure. This helps in protecting the underlying layers from water damage, such as weakening of the base and subbase layers due to moisture.

3. Flexibility: Bitumen exhibits high elasticity, which helps the road surface to withstand heavy traffic loads and temperature variations. It can expand and contract without cracking, ensuring the road's longevity.

4. Viscosity: Bitumen has a high viscosity, meaning it is thick and sticky at normal temperatures. This property allows it to coat and adhere to aggregates during the road construction process.

5. Resistance to Oxidation: Bitumen has good resistance to oxidation, which helps in maintaining its properties over extended periods. It can withstand exposure to sunlight, air, and other environmental factors without significant degradation.

Application:
Bitumen is commonly used in road construction and maintenance in the following ways:

1. Asphalt Concrete: Bitumen is mixed with aggregates such as crushed stone, sand, and gravel to create asphalt concrete, which forms the topmost layer of roads. This mixture provides a smooth and durable road surface that can withstand heavy traffic.

2. Surface Dressing: Bitumen is applied as a thin layer onto existing road surfaces to improve their durability and skid resistance. This process is known as surface dressing or chip sealing.

3. Bituminous Emulsion: Bitumen can be emulsified with water to form a bituminous emulsion. This emulsion is used for surface treatments like slurry seals and micro-surfacing, which help in preserving and extending the life of roads.

Conclusion:
Bitumen is a crucial petroleum product used for surfacing roads. Its adhesive, waterproofing, and flexible properties make it an ideal choice for road construction and maintenance. By using bitumen, we can ensure the durability, safety, and longevity of road surfaces, providing a smooth and reliable transportation network.