Consider the following:
1. Whipped ice-cream
2. Fruit jellies
3. Milk
4. Cake
5. Eggs
Which among the above is / are colloids?

Answer: [C] Only 1, 2, 3 & 5

A colloid is a heterogeneous mixture of two substances of different phases. Shaving cream and other foams are gas dispersed in liquid. Jelli, toothpaste, and other gels are liquid dispersed in solid. Dough is a solid dispersed in a liquid. Smoke is a solid dispersed in a gas. A colloidal system, which has liquid as the dispersed phase and solid as the dispersion medium is known as gel. Mixture in which the dispersed phase (relatively large particles) is distributed throughout a dispersing medium or a continuous phase (a solvent like medium) is called a colloid. Electrophoresis helps in determining the sign of the electric charge on the colloidal particles.

This question is a part of GKToday's Integrated IAS General Studies Module