Register for free to see more content

### Theory:

Fire is one of the vital forces in nature. Let us look at some of the mythological stories of fire; in Greek mythology, it is known that fire was stolen by Prometheus from god and was given to humans.

In Native American, it is known that animals like wolves and woodpeckers bought fire from evil by stealing and giving it to human use.

Many scientists believe that fire was discovered during the early stone age. It is believed that Homo Erectus are the people who found fire and controlled it.

Archaeologists discovered support for the theory of controlled fire at South Africa's Wonderwerk Cave and Kenya's Lake Turkana.

There is evidences that usage of fire dates back to millions of years ago, as in the case of the formation of fossil fuels.

Some of the usages of fire in the stone age is to stay away from animals, keep them warm and cook.

Burning wood

FUEL: They can be solids, liquids or gases and are flammable in nature, such as petrol, diesel, CNG, LPG, coal, wood, etc.

OXYGEN: Atmospheric air contains $$21%$$ of ${O}_{2}$,  and for burning, it requires $$16%$$ of ${O}_{2}$; less than this, the fire puts off by itself.

HEAT: To reach the ignition temperature, a heat source is a must, for example, electrical sources, frictions etc.

We have learnt that for any substance to burn, it requires three essential elements air, oxygen and fuel, and this is known as the fire triangle. Here fuel vaporises and combines with oxygen to form fire, and this is a chemical reaction.

The chemical process in which any substance reacts with ${O}_{2}$ to provide heat is known as combustion.