Science MCQ

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

Biogas can be produced from raw materials such as agricultural waste, manure, plant material, green waste or food waste. It is a renewable source of energy. Natural gas, coal gas and petroleum gas are fossil fuels and are nonrenewable sources of energy.

Charcoal is mostly pure carbon which is made by cooking wood in a low oxygen environment. This process can take days and burns off volatile compounds such as water, methane, hydrogen, and tar.
Petrol, coke and coal are fossil fuels which are formed from the dead remains of living organisms or fossils.

Carbonisation is the process by which plant material or vegetation buried deep under the earth was slowly converted into coal.
Since, coal was formed from the remains of vegetation, it is also known as fossil fuel.

Natural gas is a fossil fuel other than coal and petroleum. Petroleum can be extracted with giant drilling machines. The layer containing petroleum oil and natural gas is above that of water.

Many useful substances are obtained from petroleum and natural gas.
These are termed as ‘Petrochemicals’. Due to its great commercial importance, petroleum is also called ‘black gold’.

Petroleum can be extracted from under the sea bed. It can be extracted with giant drilling machines. The layer containing petroleum oil and gas is above that of water.

Water is an inexhaustible natural resource because it is available abundantly in nature.