• Written By Insha_S
  • Last Modified 07-05-2024

Physical Nature of Matter


The matter is made up of minuscule particles. The matter is classified into three categories based on the arrangement of these particles: solids, liquids, and gases. These are also known as matter’s physical states. This categorisation also includes differences in physical qualities like mass, volume, form, stiffness, density, and particle arrangement. Plasma and Bose-Einstein Condensate are two additional states of matter.

Three states of matter arise due to the differences in interparticle distances, differences in interparticle forces of attraction and differences in kinetic energies of the constituent particles.

Classification of Physical Nature of Matter

The solids, liquids and gaseous forms of matter have different properties. The characteristic properties of solids, liquids and gases are given below.

Physical Nature of Matter: Solid-State

Students can go through the below table to understand the characteristics of solids in the physical matter:

Solids have a fixed shape: Solids have a fixed shape and do not change their structure even when put in different containers. Some solids can change their shape under force but retain the same when the applied force is removed.

For example: By applying force, we can stretch a rubber band. However, when the stress force is removed, the rubber band regains its original shape. Such solids are known as elastics. In case of excessive force is applied, the elastic might break.

Solids have fixed volume: The interparticle spaces between their particles are fixed. Hence a solid has a fixed volume.

Solids cannot be compressed: Even when force is applied, it becomes difficult to compress a solid. It is because the particles in solid are so closely packed that they do not come closer or when they do come closer when very high pressure is applied.

For example, a stone can not be compressed by applying hand pressure. On the other hand, a sponge made from rubber material can be easily compressed. As the sponge has tiny holes throughout the body, the pressure has applied, the air from the hole is expelled out, and the sponge gets compressed.

Solids have high density: The density of a solid may be defined as the mass occupied by a solid per unit volume. Since the constituent particles in the solids are so closely packed, the density will be maximum in the solid state of a substance. Thus, the closer the constituent particles, the greater the density.

Solids have a negligible kinetic energy of the particle: The kinetic energy deals with the movement of the particles from one place to another. Since the constituent particles in the solids are so closely packed, they have negligible kinetic energy.

Solids do not have the property of diffusion: As the solids have negligible kinetic energy of the particles, there is hardly any diffusion due to the absence of vacant spaces between the constituent particles.

Solids do not fill the container: A solid does not fill its container because its particles are held tightly by strong interparticle forces and cannot leave their positions to fill the container.

Solids do not flow: Solids do not flow because their particles are held very firmly and cannot leave their fixed positions.

Examples of solids: Stones, wood, metals like iron, copper, nickel, etc.

Physical Nature of Matter: The Liquid State

In the liquid state of a substance, both these characters are different. The liquid state in the physical nature of matter is less rigid than the solids, and the molecular motion is also comparatively more. These characteristics in the liquid state are because of weaker interparticle forces. Students can go through the below-mentioned steps to know the characteristics of liquids in the physical matter:

Liquid does not have a fixed shape: Liquid does not have a fixed shape and takes up the shape of any container they are poured in. It is because the interparticle forces are not very strong, and the particles in one layer can easily slide over the other layer.

Liquids have a fixed volume: Since the interparticle forces between the liquid particles are powerful, the pressure applied cannot overcome these forces. Therefore, the fluid keeps its volume.

Liquids cannot be compressed: The particles in the liquid are still close together and process very small spaces between them. 

Liquids have fluidity and not rigidity: Unlike solids, liquids have fluidity and are not rigid because they tend to flow. It is due to lesser interparticle or intermolecular forces present in the liquid state compared to the solid-state. However, the liquids differ in their relative fluidity. For example, water flows faster than honey because the particles in honey are heavier and more closely packed.

Liquids have a lesser density than solids: As compared to solids, liquids are generally light. It is because of a greater number of interparticle spaces in the liquid state than in the solid-state of the same substance. But there are certain exceptions as well. Ice floats over water. Both are chemically the same and are made from H2O-H2O molecules. The structure of ice is more porous as compared to that of water. Therefore, for a given mass, the ice volume is more than water, and its density is comparatively less. As a result, ice floats over water.

The kinetic energy of the particles in the liquid state is more than in the solid state: The particles in a liquid state are less closely packed compared to the solid state. As a result, the interparticle forces are weaker. Therefore, the kinetic energy of the particles in the liquid state of a substance is more than in the solid state. It further increases with the rise in temperature rise.

Particles in the Liquid State can Easily Diffuse: Due to lesser interparticle forces of attraction, the particles in a liquid state can diffuse more readily than in the solid-state of a substance. It also helps in intermixing certain liquids.

For example, water and alcohol are both liquids and can easily mix to form a liquid mixture or a solution. Water particles can easily move into vacant spaces present in alcohol and vice versa. In addition, these particles of solids and gases can also diffuse into the liquids. That is how both of them dissolve in liquids.

Physical Nature of Matter: Gaseous State

The interparticle forces hold the different particles in the gaseous state together at the minimum. As a result, rigidity is the minimum while fluidity is the maximum. The important properties of this state of matter are listed. Students can go through the below information to know the characteristics of gases in the physical matter:

Gases do not have a fixed shape: Gases have no shape of their own. They acquire the shape of the container in which they are filled or kept.

Gases have maximum fluidity and least rigidity: Since the interparticle spaces are the maximum in the gaseous state, the attractive forces are the least. As a result, the fluidity is very large while rigidity is negligible.

Gases do not have a fixed volume and are highly compressible: Since the interparticle distance in the gaseous state is very large, we can change gases by altering the pressure. Thus, gases can be compressed to a large extent by applying pressure. Hence, a change in pressure can bring a volume change, or we can say that gases do not have a fixed volume.  

Gases are generally very Light: Compared to the solids and liquids, the gases are usually very light. The interparticle spaces are large. As a result, the particles in a gas are far separated, and the volume of a given mass of a gas is quite large. The density of the gas is very small, and the gases are, therefore, light.

The kinetic energy of the particles in the gaseous state is very high: Among the three states of matter, the kinetic energy of the particles is the maximum in the gaseous state, and the interparticle forces are very weak. As a result, a gas’s particles or molecules can move relativelyly from one place to the other. Their translatory motion is large and kinetic energy is relatively high. It can further increase when the temperature of the gas is increased.

Gases exert pressure: The pressure of a gas is because of the hits that its particles record on the walls of the container. Since particles in a gas have high kinetic energy, they strike the walls of the container with force. As a result, they exert pressure. 

Gases diffuse very rapidly: Since the interparticle spaces are very large and interparticle forces are quite weak, the particles of one gas can readily move into the empty spaces of another gas. That is why the diffusion is maximum among the gases. For example, the smell of food, particularly fish being cooked in the kitchen, spreads in the lobby and even in different rooms because of diffusion. The food particles with specific smells diffuse into the air, so their smell can be felt even from a distance. Similarly, the fragrance of a burning incense stick spreads all around due to the diffusion of the smoke released from the incense stick into the air.

Gas kept in a container fills it completely: That is rather surprising because the actual volume of the gas molecules is very small compared to the intermolecular space. However, the molecules or particles of the gas move quickly and throughout the container in no time. Examples: Air is a typical example of a gaseous state. It is a mixture of several gases like nitrogen, oxygen, carbon dioxide, inert gases, etc.

We hope the above article helped you.

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