Define the following terms:a) melting point     b) boiling point        c) evaporation


All the three terms are related to phase change.
Boiling point: The temperature at which a liquid’s vapour pressure equals the pressure of the gas above it is known as the boiling point. The temperature at which a liquid’s vapour pressure equals one atmosphere is known as its normal boiling point (760 torr).

Melting point: The melting point of a liquid is the temperature at which it transforms from a solid to a liquid at atmospheric pressure. This is the point where the liquid and solid phases are in balance. The substance’s melting point varies with pressure and is reported at standard pressure.

Evaporation: Evaporation is the transformation of a liquid substance into a gaseous state as a result of a change in temperature or pressure.

Final answer: Hence, melting point is change of solid to liquid, boiling point is change of liquid to vapour and evaporation is somehow similar to boiling but in this the process of changing of liquid to vapour take place on the surface.