Membrane bombardment theory of semipermeable membrane
Membrane bombardment theory:
According to this theory, Osmosis arises due to unequal bombardment of solvent molecules on both sides of a semipermeable membrane. Since, the surface covered by solvent molecules is more in solvent side than in solution side, there are lesser bombardment per unit area of the surface on the solution side than on the solvent side. Hence, due to the unequal bombardment, the solvent molecules on the solvent side will diffuse more faster through the membrane than on the solution.