Post by penserstudypoint.com
Fire is a chemical reaction that occurs very quickly, and in the process, gives off heat and light.
Three things are necessary for this reaction to occur- fuel, oxygen, and heat.
Fuel whether it is paper or wood-by itself will not catch fire. It is only when the fuel is heated, and becomes hot enough, that the oxygen in the air combines freely with it to burst into flames.
The reason, fire is hot is because it releases a lot of energy that has been stored in fuel. For example, energy from sunlight is stored in the wood that is used as fuel.
When energy is released very quickly, heat and light are produced.