Solution, Colloid and Suspension

Solution Suspension Colloid
Appearance Clear, transparent and homogeneous Cloudy, heterogeneous, at  least two substances visible Cloudy but uniform and homogeneous
Particle Size molecule in size larger than 10,000 Angstroms 10-1000 Angstroms
Effect of Light
Tyndall Effect
none – light passes through, particles do not reflect light variable light is dispersed by colloidal particles
  Effect of Sedimentation none particles will eventually
settle out

In summary:
A solution is always transparent; light passes through with no scattering from solute particles, which are molecule in size. The solution is homogeneous and does not settle out. A solution cannot be filtered but can be separated using the process of distillation.
A suspension is cloudy and heterogeneous. The particles are larger than 10,000 Angstroms, which allows them to be filtered. If a suspension is allowed to stand, the particles will separate out.
A colloid is intermediate between a solution and a suspension. While a suspension will separate out a colloid will not. Colloids can be distinguished from solutions using the Tyndall effect. Light passing through a colloidal dispersion, such as smoky or foggy air, will be reflected by the larger particles and the light beam will be visible. A hydrocolloid can simply be defined as a substance that forms a gel when it is exposed to water. Such substances include both polysaccharides and proteins.