Write the dispersed phase and dispersion medium of milk.

Hint: To solve this problem, firstly we should understand the concepts behind colloids, emulsion, dispersed phase and dispersion medium and then we will be studying these properties of Milk (as asked in our question) by which we can approach the answer.

Complete answer:
> Colloidal solution: colloidal solution is a heterogeneous mixture. Particle size of substance a. i.e. between $1 - 1000nm$. It is a solution in which we have the material evenly suspended in the liquid and hence it appears to be homogeneous.
For example: Soap, starch solution, blood, milk etc.
> Dispersed phase: Dispersed phase is in the droplet form that is suspended in dispersion medium is called the dispersed phase.
> Dispersed medium: The medium in which the colloidal particles are dispersed is called the dispersion medium.
Example: Starch and water represent the dispersed phase and the dispersion medium in a starch solution.
> In the case of milk, milk is an emulsion in which both dispersed phase and dispersed medium are liquid states. In milk liquid fat is dispersed in water so that the fat is the dispersed phase and water represents the dispersion medium. (As milk is a colloidal mixture, including liquid fat and water).

Note - An emulsion is a mixture of two or more liquids that are immiscible owing to liquid- liquid phase separation. Milk is an emulsion whose fat globules are dispersed in an aqueous solution. The fat globules, instead of fusing, form a separate layer because they are protected by a membrane layer which keeps the fat particles separate from the water phase. Emulsion is commonly used in pharmaceutical industries for the manufacturing of drugs to increase their stability generally used in making emulsions.