1. Colloids have optical property. When a homogeneous solution is seen in the direction of light, it appears clear but it appears dark in a perpendicular direction.
2. When light passes through colloidal solution, it is scattered in all direction and it is known as Tyndall effect.
3. The colloidal particles absorbs a portion of light and remaining portion is scattered from the surface of the colloid. Hence the path of light is made clear.
