The process of burning of a substance in the presence of oxygen/air to produce heat and light is called __________ .

The lowest temperature at which a substance catches fire is called its _______ temperature.

A _______ is the region of combustion of gaseous vapours with the evolution of heat and light.

The type of combustion in which any substance starts to burn of its own is called __________.

The substances that undergo combustion are called __________ substances.