Question

Are these a colloid, suspension, or solution?
a) milk in water
b) chalk powder in water
c) copper sulfate in water

Answer 1

Hint: A colloid has a dispersed and continuous phase, whereas a solution only has one phase with the solute and solvent. Individual molecules or ions make up a solute in a solution, whereas colloidal particles are larger. The sodium chloride (NaCl) crystal dissolves in a solution of salt in water, and the $N{{a}^{+}}$ and $C{{l}^{-}}$ ions are surrounded by water molecules.

Complete answer:
A colloid is a combination in which one component is suspended in another by microscopically distributed insoluble particles. Some definitions, however, stipulate that the particles must be dispersed in a liquid, while others broaden the concept to include aerosols and gels. The phrase colloidal suspension clearly refers to the entire combination (although a narrower sense of the word suspension is distinguished from colloids by larger particle size).
A suspension is a heterogeneous combination of a fluid containing big enough solid particles to cause sedimentation. The particles may be visible to the human eye, must be bigger than one millimetre, and will settle eventually, however the combination is only classed as a suspension if the particles have not settled out.
A solution is a sort of homogenous mixture that is made up of two or more components. A solute is a material that is dissolved in another substance, known as a solvent, in such a combination. The mixing of a solution takes place at a scale where the effects of chemical polarity are present, resulting in solvation-specific interactions.
A is milk in water; however, milk is already a mixture of lipids and water, therefore it does not need to be in water. Because milk is a one-hole solution rather than two layers, it is due to an emulsion. A colloid is simply a combination in which scattered insoluble particles are suspended in another material.
Because chalk powder is only slightly soluble in water, it will produce a suspension. A suspension is a liquid-solid solution in which the solid floats around in the liquid rather than dissolving in it.
Copper sulphate is a solution because it is very soluble in water. A solution is a homogeneous mixture of two or more compounds.
Hence a = colloid, B = suspension C = solution

Note:
Colloidal phase separation, like compartmentalization via lipid bilayer membranes - a kind of liquid crystal - is a key organising mechanism for compartmentalising both the cytoplasm and nucleus of cells into biomolecular condensates. The term "biomolecular condensate" has been used to describe macromolecule clusters that form within cells as a result of liquid-liquid or liquid-solid phase separation. Colloidal phase separation and the production of biomolecular condensates are greatly aided by macromolecular crowding.