Suspensionis a heterogeneous mixture in which particle size of one or more components is greater than 1000 nm. This solution is an example of suspension. Contrary to True Solution, particles of suspension are big enough to be seen with naked eye. They are not stable as the particles of suspension settle under water due to influence of gravity.The particles of a suspension can neither pass through ordinary filter paper nor through animal membranes.Suspension may or may not show Tyndall effect. When mud is dissolved in water and stirred vigorously, particles of mud are distributed evenly in water. After some time, the particles of this solution settle under water due to influence of gravity.Turmeric in water, sand in water are some examples of suspensions.
Colloidal Solutionappears to be homogeneous but is actually a heterogeneous mixture in which particle size of substance is intermediate of true solution and suspension i.e. between 1-1000 nm. Just like true solutions, Colloidal particles are small enough and can neither be seen through naked eye nor by an ordinary microscope. They easily pass through filter paper. But colloidal particles are big enough to be blocked by parchment paper or animal membrane.They are stable as particles do not settle down when the solution is left standing.Colloids show Tyndall effect.Smoke from a fire is example of colloidal system in which tiny particles of solid float in air.
