The matter of solid and liquid states can be relatively low viscosity and density and great expansion and contraction with changes in temperature and pressure. The gaseous state can be able to diffuse quickly. It can be distributed uniformly throughout any container. A pure gas can be made up of individual atoms. Example: noble gas or atomic gas like neon.
Gases do not have fixed shape:
It does not have any shape in nature. The shape of the gas can be measured by the gas can be filled or contained in any shape. For example we often use balloon filled with air inside.
Gases have minimum fluidity and least rigidity:
There may be more interparticle spaces in the gaseous state with maximum range. The least one is the attractive force. Therefore, fluidity is very large compared to rigidity is negligible.
Gases do not keep their volume and are highly compressible:
In gaseous state, the interparticle distances are very large. By altering the pressure the gaseous state can be changed. Therefore, gas can be compressed to large extent by applying pressure. The change in pressure can bring change in volume.
Gases are generally very light:
The gases are very light as compared to solids and liquids. The interparticle spaces are large. The volume of a given mass of a gas can be quite large and the particle of a gas is very light.
Kinetic Energy of a particle in the gaseous state is very high:
Inter particle forces are very weak. Kinetic energy of the particle is maximum in the gaseous state. The particles or molecules of a gas can move freely from one place to another. The kinetic energy is high and translator motion is large. When the temperature of the gas is increased, kinetic energy also increased.
Gases exert pressure:
Because of hits in a pressure of a gas, their particles can be recorded on the walls of the container. Particles in a gas have kinetic energy; it can strike the walls of a container with force. The container can be hit, which a greater number of hits recorded per unit area of the wall of the container. The pressure of the gas will be more.
Gases diffuse rapidly:
The particle of one gas can move into the empty spaces of another gas.
Air is one of the common examples of oxygen, carbon dioxide, nitrogen and inert gases, sulphur dioxide, ammonia, hydrogen, chlorine, etc.