Principle of Combustion 

• Combustion is defined as  Rapid oxidation generating heat, or both light and heat, slow oxidation also  accompanied by relatively less heat or no light
• Different color in combustion is observed  because of light emitted by different excited radicals

•  Combustible substance: C, H, Mg, S and hydrocarbons etc.  ( Fuel is a combustible substance that has Low Electronegativity )
•  Oxidizer: Oxygen which has the second highest electronegativity after Fluorine

 Essential conditions for combustion to occur

1. Presence of  fuel
2.  Presence of oxidizer (it can be air)
3.  Right proportions of fuel and oxygen
4.  The proportion is decided by the flammability limit.
5.  Ignition energy is essential to provide heat energy for the initiation of burning