Fuels and fossil fuels - class-VIII

Fuel that is formed from the decay of the dead plants and animals millions of years ago is called fossil fuel. Examples include coal, petroleum, natural gas.

Seaweed can be used for the production of biofuel. Methane can be produced via anaerobic digestion of seaweeds.

Charcoal is not a fossil fuel since it is obtained by partially burning the wood.

Liquid petroleum or LPG contains main components as butane and propane with butane forming the major constituents. Sometimes butane is replaced by iso-butane.

Coke is majorly used in the extraction of the metals from their ores. It is used as a reducing agent. Hence, coke is more valuable in metal extraction industry, when used as a reducing agent.

In chulhas, gaps are left between the logs are there to to decrease the ignition temperature of the fuel

Fire is indeed a chemical process of combustion, which is an exothermic reaction between a fuel and an oxidant.

Coal is a fossil fuel formed from the remains of ancient vegetation that was buried and subjected to heat and pressure over millions of years.

A) Petroleum

A chemical reaction produces energy (exothermic) when the potential energy of the products is lower than that of the reactants, meaning the energy released by forming product bonds is greater than the energy absorbed to break reactant bonds.

The energy possessed by fossil fuels such as coal, petroleum and natural gas is called the chemical energy or fuel energy. These fuels contain chemical energy stored in them.

Anaerobic decomposition of dead animals and plants along with exposure to Earth's heat and pressure resulted in buried source of energy: fossil fuels.

Coal is a fossil fuel which is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. Coal is composed primarily of carbon, along with variable quantities of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. A fossil fuel, coal forms when dead plant matter is converted into peat, which in turn is converted into lignite, then sub-bituminous coal, after that bituminous coal, and lastly anthracite. This involves biological and geological processes that take place over time. Throughout history, coal has been used as an energy resource, primarily burned for the production of electricity and heat, and is also used for industrial purposes, such as refining metals. Coal is the largest source of energy for the generation of electricity worldwide, as well as one of the largest worldwide anthropogenic sources of carbon dioxide releases. The extraction of coal, its use in energy production and its byproducts are all associated with environmental and health effects including climate change.

A non-renewable resource (also called a finite resource) is a resource that does not renew itself at a sufficient rate for sustainable economic extraction in meaningful human time-frames.
Fossil fuels are non renewable resource.
Wind and wood are renewable  as their localized replenishment can occur within time frames meaningful to humans.

Water gas, coal gas, and producer gas are all gaseous fuels, whereas coke is a solid fuel.

Charcoal, lignite, and coke are solid carbon-based fuels derived from natural sources, whereas alcohol is a liquid fuel.

fuels like petrol and wood, electricity is cheaper and produce less toxic gas when it burn.
Option C

Coke is obtained from Coal.

Petroleum is a fossil fuel formed from the remains of ancient marine organisms that were buried under layers of sediment and subjected to high pressure and heat over millions of years. Coal is derived from land vegetation, while biogas is produced from organic waste.

Petrol is a product of petroleum obtained with the help of fractional distillation petroleum is a fossil fuel taken out from various depths of earth both on land and see shore. 

Natural gas is formed by the anaerobic decomposition of organic matter, such as plant material, trapped under water or sediment. This process occurs deep underground over long periods.

Natural gas, petroleum, and uranium are non-renewable energy sources typically extracted from the earth. Wood is a renewable biomass source, making it the odd one out in this context.

When $1\ kg$ of coal is burnt the energy released is $30\ MJ ( = 3\times 10^{7}J)$.

Fuels formed under the earth by the decomposition of organic matter are called fossil fuels

Kerosene is a hydrocarbon liquid which is highly combustible. Also known as lamp oil it is used as fuel in industry as well as households.

Method used for the formation of charcoal is thermal pyrolysis.It is a processes involved in charring of wood.

The traditional chulha provides a low thermal efficiency. The efficiency of the traditional chulhas is usually around $8-10$%

All are fuels except water

Firewood is a conventional source which is non-renewable.

Conventional resources are non-renewable resources. They cannot be replenished in foreseeable future.

Oil and petroleum are referred to as black gold. When extracted, it is black in colour, however, its market value is very high like gold.

Heating value of coal is approximately $5000-6500 $  $kcal/kg$

Fuels formed due to the decomposition of dead animals and organic matter mainly in an anaerobic condition millions of years ago are fossil fuels. Coal, natural gas and petroleum are fossil fuels.

Some examples of conventional sources of energy are wood, coal, fossil fuels, petroleum and natural gas.

Sources of energy that have been used for a very long time and cannot be used or renewed again are the conventional sources of energy. Example: coal, oil and pertroleum.

Harnessing hydel power / energy is very costly procedure due to construction of large dams across the streams, clearance of vegetation for the development of the project, rehabilitation of the people living nearby the water bodies.

Diesel, gasoline, and alcohol are liquid fuels. Lignite is a type of coal, which is a solid fuel, making it the different option.

Ignition temperature is the minimum temperature at which a substance catches fire. Kerosene has a lower ignition temperature than coke, allowing it to ignite and burn more rapidly.

The destructive distillation of coal produces coal gas, coal tar, and ammoniacal liquor (often referred to as amino acid liquor in some contexts). Wood and kerosene are not products of coal distillation.

Spontaneous combustion occurs without an external ignition source. LPG requires an external spark or flame to ignite, so it is not an example of spontaneous combustion.

Coal gas and natural gas are formed under the earth by the decomposition of plant matter by anaerobic bacteria lying under the water.

Coal is a fossil fuel formed from the remains of ancient land plants and vegetation that were buried and subjected to geological processes over millions of years.

A candle flame is a yellow luminous flame because of the incomplete combustion of wax particles, which glow as they are heated.