Describe any three properties of colloids. Categorise the following examples of colloids into different categories of colloids: Jelly,fog,milk,shaving cream.

(N/A) Properties of colloids:
$(a)$ $A$ colloid is a heterogeneous mixture. The size of particles of a colloid is too small to be individually seen by the naked eye.
$(b)$ Colloidal particles are big enough to scatter a beam of light passing through them and make the path of light visible (Tyndall effect).
$(c)$ They do not settle down when left undisturbed,i.e.,a colloid is quite stable. However,centrifugation techniques can be used to separate the colloidal particles.
Categorization of examples:
- Jelly: Gel
- Fog: Aerosol
- Milk: Emulsion
- Shaving cream: Foam