Excessive use of coal and petroleum improves the quality of air.

Describe how coal is formed from dead vegetation. What is this process called?

Fossil fuels are ________, ________ and ________.

Process of separation of different constituents from petroleum is called __________.

Least polluting fuel for vehicle is ________.

Fossil fuels can be made in the laboratory.

CNG is more polluting fuel than petrol.

Coke is almost pure form of carbon.

Coal-tar is a mixture of various substances.

Kerosene is not a fossil fuel.

Explain why fossil fuels are exhaustible natural resources?