Define following. a. Brownian motion b. Chemical change c. Neutralisation reaction.

A. The uncontrolled or erratic movement of particles in a fluid due to their constant collision with other fast-moving molecules is called Brownian motion.

B. A change of materials into another, new materials with different properties and one or more than one new substances are formed is called chemical change.

C. A chemical reaction in which an acid and base quantitatively react together to form a salt and water as products is called neutralization reaction.