what is the difference between rapid combustion and exploison?
Combustion in which substance burns rapidly to produce heat and light is called rapid combustion.
Example: LPG burns rapidly to produce heat and light.
Combustion in which sudden reaction takes place on ignition of substances to produce heat, light and sound is called explosion. Explosion requires expansion of volume while this is not necessary in case of combustion.
Example: Firecracker produces heat. light and sound.