Q. 1. (a) What is a flame? What type of substance, on burning, gives a flame? (b) What is the difference between the burning of a candle and the burning of a fuel like coal?

Answer

(a) A hot glowing body of ignited gas that is generated by something on fire is called Flame. Kerosene oil and molten wax are substances that give a flame while burning.

(b) Substances which vapourize during burning produce flames, such as wax in the candle, Kerosene.

Substances which do not vapourize during burning do not produce flames. Example - coal and charcoal.