3.0 FIRE TETRAHEDRON.

            beside 3 elements there is forth element which is essential for continuation of fire once ignited.this is known as "CHAIN REACTION".
            once fire occurs the burned substunce produce lots of heat which tends to burn remaining fuel substance.this reaction occurs again and again.which is called "chain reaction".
            fire is OXIDATION process which produce heat its is also called EXOTHERMIC reaction..

OXIDATION  = EXOTHERMIC R.   = PRODUCE HEAT.
REDUCTION = ENDOTHERMIC R. = ABSORB HEAT.