If you observe around, you will find different types of matter around you. Observing around we would find that matter around us exists in three different states� solid, liquid, and gas. These states of matter arise due to the variation in the characteristics of the particles of matter. Now, let us study the properties of these three states of matter in detail.

THE SOLID STATE

The characteristics of solid-state are that it has a definite shape, distinct boundaries, and fixed volumes, that is, has negligible compressibility. Solids have a tendency to maintain their shape when subjected to outside force.

Solids may break under force but it is difficult to change their shape, so they are rigid. Having learned about the concept of solid, let us now look at some typical examples: As we all know, Rubberband, can change its shape on stretching? Is the rubber band solid?

A rubber band changes shape under force and regains the same shape when the force is removed. If excessive force is applied, it breaks. Hence rubber band is solid. But What about a sponge? It is solid yet we are able to compress it. Why? A sponge has minute holes, in which air is trapped, when we press it, the air is expelled out and we are able to compress it. Hence sponge is also solid.

THE LIQUID STATE

If we look around, we will find that liquids have no fixed shape but have a fixed volume. They take up the shape of the container in which they are kept. Liquids flow and change shape, so they are not rigid and hence are also called fluids.

Let us now understand another aspect about the different states of matters, From the previous modules, we have learned that solids and liquids can diffuse into liquids. Also, we find that the gases from the atmosphere also diffuse and dissolve in water.

Do you know these gases, especially oxygen and carbon dioxide, are essential for the survival of aquatic animals and plants? All living creatures need to breathe for survival. And do you know, aquatic animals can breathe underwater due to the presence of dissolved oxygen in the water?

Thus, we may conclude that solids, liquids, and gases can diffuse into liquids. The rate of diffusion of liquids is higher than that of solids. This is due to the fact that in the liquid state, particles move freely and have greater space between each other as compared to particles in the solid state.

THE GASEOUS STATE

Have you ever seen a hot air balloon? Do you know, what is inside it? Yes, it is the gas that occupies the space inside it. From earlier classes, we have observed that gases are highly compressible as compared to solids and liquids. It is due to the large spaces inside the gases, that allow them to compress to large extent.

The liquefied petroleum gas (LPG) cylinder that we get in our home for cooking or the oxygen supplied to hospitals in cylinders is a compressed gas. Students, Compressed natural gas (CNG) is used as fuel in vehicles. Due to its high compressibility, large volumes of gas can be compressed into a small cylinder and can be transported easily. You would have often observed that you come to know about what is being cooked in the kitchen without even physically going there.

Can you tell how does this smell reaches you?

The particles of the aroma of food mix with the particles of air and spread across from the kitchen to finally reach us and even farther away. Due to this, we are able to smell the taste of the food. Due to the high speed of particles and large space between them, gases show the property of diffusing very quickly into other gases.

In the gaseous state, the particles move about randomly at high speed. Due to this random movement, the particles hit each other and also with the walls of the container. And student do you know, what is the pressure exerted by the gas? The pressure exerted by the gas is because of this force exerted by gas particles per unit area on the walls of the container.

Read More: Interconversion of States of Matter - Effect of Temperature and Pressure