how many types of combustion are there explain them
There are three different types of combustion:
1) Spontaneous combustion
The combustion in which substances suddenly burst into flames, without the application of any apparent cause is called spontaneous combustion. For example, sodium and phosphorus burn spontaneously in air, even when no external heat is provided to them.
2) Rapid combustion
The combustion in which substances burn rapidly to produce heat and light is called rapid combustion. In rapid combustion, external heat must be supplied so that the substances can burn. For example, when a burning matchstick is brought near a gas stove (with its knob turned on), LPG burns rapidly to produce heat and light.
The combustion in which sudden reactions take place on ignition of some substances to produce heat, light, and sound is called explosion. For example, fireworks on ignition produce heat, light, and sound. Other substances such as dynamite also explode when ignited to produce huge amounts of energy. Dynamite is used to explode mountains to build roads, train tracks, and tunnels in hilly areas.