what does the unbalanced bombardment of colloidal particles mean?
True solution: A true solution is a homogeneous solution in which the solute particles have diameters between 0.1 nm to 1nm i.e., the solute particles are of molecular dimensions.
Colloidal Solution: Colloidal solution or colloidal state or colloidal dispersion, represent an intermediate kind of a mixture between true solution and suspension. The size of a colloidal particle lies roughly between 1-100 nm.
The dispersion medium is present continuously and hence when the colloidal particles hits one dispersion medium molecules it moves in a direction and finds another molecule of dispersion medium and hence the movement is zigzag and random. So the Brownian movement is explained by the unequal bombardment of the dispersed phase with the dispersion medium. In true solution, particles size is smaller than colloidal particles so bigger particles are hard to move while smaller particles are easy to move, so true solution has high value of brownian movement.