Match the following. Column A Column B Explosion Coke The outer zone of flame sudden release of heat Fossil fuels CNG Non-polluting fuel Exhaustible Hard and dry fuel Blue in colour

An explosion is a type of combustion when an object burns all of a sudden with the release of heat, light, sound, and a large amount of gas. Hence, the explosion is accompanied by a sudden release of heat. The outer zone of a flame is in direct contact with air, and hence it gets the maximum supply of air. Therefore, the wax vapours in the outer zone undergo complete combustion, and leave no residue behind due to which the flame appears clear and blue. Hence, the outer zone of the flame is blue in colour. Fossil fuels are formed from the remaining plants and animals which buried under heavy pressure over a million years ago. Hence, they are exhaustible fuels since there is no other source of it to recover them once they get finished. Non-polluting fuels produce less undesirable substances on burning, and hence, they are considered to be less harmful to our environment. CNG is used as an alternative fuel in the vehicles. It produces no smoke, and therefore, it is an environment-friendly gas. Hard and dry fuels are solid and dry in nature. The properties of coke match the properties of hard and dry fuels since it is made up of carbon and has no moisture present in it. Column A Column B Explosion Sudden release of heat The outer zone of flame Blue in colour Fossil fuels Exhaustible Non-polluting fuel CNG Hard and dry fuel Coke