Question

Comment upon the following: rigidity, compressibility, fluidity, filling a gas container, shape, kinetic energy and density.

Answer 1

Hint: To solve this question we have to know about the three states of matter that are solid, liquid and gas. The conditions that are given above are compatible here such as a substance can be transformed from its solid state to the liquid state and also the other way around. The change in the liquid state to its vapour phase and the other way around is also conceivable.

Complete step by step solution:
Let us comment on each of the given topic one by one,
(a) Rigidity:- Rigidity is defined as the tendency of matter which has the capability to resist a change in shape and it is shown by solids. As we know that solids are highly rigid and liquids are less rigid as compared to solids whereas gas has a very low property of rigidity in them.
(b) Compressibility:- Compressibility is defined as the power to reduce the gas to a lower volume when external force is applied on them. Solids show negligible property of compressibility and liquids have low compressibility whereas gases are easily compressible because there are large empty spaces present between the particles of gases.
(c) Fluidity:- Fluidity is defined as the tendency to flow and it is a property which is shown by liquids and gases. Solids have less fluidity in them. Liquids as well as gases have the property to change their shape when external force is applied on them.
(d) Filling a gas container:- Filling a gas container means the attainment of the shape of the container by the gas. As we know that solids do not need a container to contain them whereas liquid needs a container to contain them while gases have the property to fill the container completely.
(e) Shape:- shape is defined as the definite boundary. As we know that solids have definite boundaries as well as definite shape whereas liquids and gases do not have fixed shape and boundaries. They have the property to acquire the shape of the container in which they are kept.
(f) Kinetic energy:- Kinetic energy is defined as the energy of motion and as we know that the particles of matter are always in motion so they have kinetic energy. Solids have least kinetic energy because particles are bound to each other with strong inter particle force of attraction whereas the kinetic energy of particles in liquids are more as compared to solid while the gas particles have a much higher value of kinetic energy.
(g) Density:- Density is defined as the mass per unit volume. It refers to how compact a substance can be. Therefore the solids have high density as comparison to liquid whereas gases have least density.

Note: Fluidity is the reverse of rigidity. As we know that the kinetic energy depends on the temperature so when temperature increases the kinetic energy of the particle in the matter also increases. Here we have discussed only three states of matter but at the extreme conditions two more states of matter exist that are plasma and Bose-Einstein condensate.