Question

Process of change of state from gaseous state to liquid is called:
(A) Freezing
(B) Sublimation
(C) Boiling
(D) Condensation

Answer 1

Hint When heat is applied to the particles of a substance they gain thermal energy and start vibrating or gain kinetic energy which causes them to move around. This, on a larger scale, results in the change in temperature or change in state of the substance.

Complete Step by step answer
There are three states of matter-
The solid state- In the solid state, particles are closely packed together by the intermolecular forces of attraction and cannot move from their places. A solid has a definite shape and a definite volume. When heat is provided to a solid object the particles present in it start vibrating faster in their places. When heat is increased, the solid state converts into the liquid state, this process is called Melting.
The liquid state- In the liquid state, particles are still close to each other but they are free to move in their directions within the liquid substance. A liquid does not have a definite shape but has a definite volume. When heat is provided to a liquid substance, the particles present in it start moving faster. When the heat is increased, the liquid state converts into a gaseous state, this process is called Boiling or evaporation. When a liquid is cooled it converts to the solid state, this process is known as Freezing.
The gaseous state- In the gaseous state, particles are situated very far away from each other that there is no or very little intermolecular attraction between them. The particles can move anywhere in the space freely, thus a gas does not have a definite shape or definite volume. When heat is provided to a gaseous state, the pressure exerted by the gas is increased, it does not change to any other state of heating. But when a gas is cooled, it changes from the gaseous state to the liquid state, this process is known as Condensation.
Thus the process of change of state from gaseous state to liquid is called condensation.

Option (D) is correct.

Note Evaporation occurs when the particles of a liquid slowly escape in the air through the surface of the liquid, whereas boiling is the process when the temperature of a liquid is so high that it converts into the gaseous state by itself. Sublimation is a process that is similar to evaporation, it involves a solid converting into gas.