Statement - I : Colloids scatter light while true solutions do not.
Statement - II : The particles in the colloidal sol move much slower than that of the true solution

Statement I is true. Colloids are heterogeneous mixtures in which the dispersed phase consists of particles that are larger than molecules but too small to be seen by the naked eye. When light passes through a colloid, the particles scatter the light in all directions, causing the colloid to appear turbid or opaque. In contrast, true solutions are homogeneous mixtures in which the dispersed phase consists of molecules that are small enough to remain dissolved and not scatter light.

Statement II is not necessarily true. The particles in a colloid can move at varying speeds depending on the size and type of particles, as well as the temperature and concentration of the colloid. Some colloidal particles can move relatively quickly due to Brownian motion, while others may move more slowly or even be stationary. Similarly, the particles in a true solution can also move at varying speeds depending on the properties of the solute and solvent. Therefore, the statement that particles in a colloid move much slower than those in a true solution is not always accurate.