Fill in the blanks:
(a) Evaporation of a liquid at room temperature leads to the ___ effect.
(b) At room temperature, the forces of attraction between the particles of solid substances are_____ than those which exist in the gaseous state.
(c) The arrangement of particles is less ordered in the ____ state. However, there is no order in the _____state.
(d) ______ is the change of gaseous state directly to solid state without going through the ____state.
(e) The phenomenon of change of a liquid into the gaseous state at any temperature below its boiling point is called______
(a) Evaporation of a liquid at room temperature leads to the cooling effect.
Since some heat energy is taken from the liquid during the process of evaporation. Due to evaporation, the temperature of the remaining liquid is reduced.
(b) At room temperature, the forces of attraction between the particles of solid substances are stronger than those which exist in the gaseous state.
The forces of attraction between the particles of a gas are minimum, intermediate in case of a liquid and are maximum in a solid. Hence, in case of oxygen ‘forces of attraction’ are minimum since it is a gas. On increasing the temperature of solids, the kinetic energy of the particles increases. Due to the increase in kinetic energy, the particles start vibrating with greater speed. The energy supplied by heat overcomes the forces of attraction between the particles. The particles leave their fixed positions and start moving more freely.
(c) The arrangement of particles is less ordered in the liquid state. However, there is no order in the gaseous state.
The forces of attraction between the particles of a gas are minimum, intermediate in case of a liquid and are maximum in a solid. Hence, in case of oxygen ‘forces of attraction’ are minimum since it is a gas.
(d) Sublimation is the change of gaseous state directly to solid state without going through the liquid state.
Sublimation is a physical process where solid changes directly into a gas without passing through the intermediate liquid phase. For example, solid carbon dioxide also known as Dry Ice changes into gas directly without passing through the liquid phase.
(e) The phenomenon of change of a liquid into the gaseous state at any temperature below its boiling point is called evaporation.
The particles of matter are always moving. In case of any gas, liquid or a solid at any given temperature particles have different kinetic energy. A small fraction of particles at the surface of a liquid has higher kinetic energy. Due to higher kinetic energy, these particles are able to break away from the forces of attraction of other particles and gets converted into vapour. This phenomenon of change of a liquid into vapours at any temperature below its boiling point is called evaporation.