​Substances that burn in the presence of air and oxygen to produce heat and light

is called substances.

EX:Wood, paper,Kerosene, LPG.etc

​Combustible

​Substances that do not burn in the presence of air or oxygen to produce heat and light are called non-combustible substances.

EX: Water,sand,glass,cement . etc

Non Combustible

​TYPES OF COMBUSTION

​RAPID COMBUSTION

​In this type of combustion, heat and light are produced in a short span of time. The combustion of LPG which produces heat and light instantly is an example of rapid combustion.

​EXPLOSION

​This type of combustion is accompanied by heat, light, and sound with the liberation of a large amount of gas. Firecracker is an example of an explosion. An explosion can also occur upon the application of pressure.

​Spontaneous Combustion

​In this type of combustion, substances catch fire on their own. For example, white phosphorus catches fire on its own at room temperature.

​Combustion of HYDROCARBONS is of two types: Complete Combustion and Incomplete Combustion.

​Complete Combustion

​This type of combustion takes place in an adequate amount of oxygen. It results in the formation of heat, light, water, and carbon dioxide.

​INCOMPLETE COMBUSTION

​This type of combustion takes place in an inadequate amount of oxygen. It results in the formation of heat, light, water, soot, and carbon monoxide.