Question

Which criteria are responsible for deciding whether a heterogeneous mixture is a colloid or a suspension?

Answer 1

Colloids are mixtures with particle sizes comprised of clumps of molecules, and it may look homogeneous to the naked eye; however two examples are fog and milk. The particles in a colloid are the right size to scatter light. Colloids don't separate on standing and aren't separated by filtration.

Suspensions are homogeneous mixtures and the particle size is great enough so they are visible to the naked eye. Two examples of this are blood and aerosol sprays. Suspensions are "murky" or and or "opaque" and don't transmit light. Suspensions separate on standing. The mixture of particles can be separated by filtration.