The convection can occur most likely in liquids and gases.
Explanation
The process of heat transfer can be classified in three types:
(i) conduction,
(ii) convection and
(iii) radiation.
Mostly we term the mechanism of heat transfer as conduction which occurs in solids.
The densely packed atoms in solids vibrate when heat energy is applied on them and while vibrating the atoms will transfer energy from one atom to another atom on collision. This is the mechanism in conduction.
But in liquids and gases , the probability of collision of vibrating atoms are very less as the atoms are loosely arranged in liquids and gases. So in them convection method is used for the transfer of heat energy.
The heat energy will be carried by the molecules while moving in their path and thus the heat energy will be transferred by convection in liquids and solids.
