Question

GASES UNLIKE SOLIDS AND LIQUIDS EXERT PRESSURE ON THE WALLS OF THE CONTAINER.

Answer 1

this is cause gases are freely moving particles.
unlike solids and liquids they have freedom to move around anywhere freely
that is the reason whenever they come in contact with anything they exert force on it

Answer 2

as gaseous molecules are in great motion they posses high kinetic energy Hence They apply pressure on the walls of the container