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

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

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

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

The substances that undergo combustion are called __________ substances.