Question

what is convection? explain it in 250 words.
plz don't answer in less than 250 words

Answer 1

Convection: Molecules, on gaining energy, become lighter and rise up, while the cold molecules come down.

Answer 2

In liquids, heat is transferred by means of convection. When heat is supplied at the bottom of a container, water at the bottom warms up first. As warm water has lower density it moves upwards and it is replaced by the surrounding cold water. Owing to difference in density currents are formed and heat is transferred. Such transfer of heat by means of currents is called convection. Convection of heat also requires a medium which may be in liquid or gaseous form. In liquids and gases heat is transferred by convection.