There are three states of matter:
- Solid state
- Liquid state
- Gaseous state
What are the properties of solids (First states of matter)?
Solids possess the following properties:
- Solids are rigid and incompressible. Because in solids, the constituent particles are closely packed and there is virtually no space between the particles. So, solids cannot be compressed. A sponge can be compressed easily, because it has small pores in it. Air is trapped in these pores. When a sponge is pressed, air is expelled out and it gets compressed.
- A solid has a definite shape and volume. Because in solids, the constituent particles are held together by a strong cohesive force. For example, salt and sugar are solids because the shape of each individual crystal remains unchanged.
- Solids in general have higher density. Solids have higher density than liquids and much higher than that of gases. This is because the particles in solids are packed tightly due to strong intermolecular forces. Density is defined as mass per unit volume.
- In solids, intermolecular forces are strong. In solids, the constituent particles are held closely in fixed position due to a strong force of attraction. These particles, however, can rotate and/or vibrate about their mean positions. Thus, the particles in solids possess very little kinetic energy.
- Diffusion of a solid into another solid is extremely slow. The particles in solids do not move much from their fixed positions. Therefore, diffusion of one solid into another is extremely slow.
- Solids have high melting points. Due to strong cohesive or intermolecular forces, solids have high melting points.
What are the properties of liquids (Second states of matter)?
Liquids possess the following properties:
- Liquids have no fixed or definite shape. Liquids take the shape of the container in which they are placed. It is because, in liquids, the constituent particles can move over short distances, and adjust their mean positions.
- A liquid has a definite volume. In liquids, the cohesive forces are strong enough to keep the constituent particles together.
- Liquids have lower density than solids. In liquids, the particles are loosely packed. So, liquids are less dense. There are a few exceptions. The most known example is that of water. Solid water, i.e., ice, floats on water. This is because ice is lighter than water.
- Liquids are slightly more compressible than solids. Due to greater intermolecular space, liquids are more compressible than solids.
- Liquids diffuse more easily than solids. The particles in liquids move faster and more freely than those in solids. So, the particles in liquids have more kinetic energy than those in solids. As a result, diffusion in liquids is faster than in solids. The diffusion in liquids depends upon the thickness, called as viscosity, of the liquids.
- Liquids flow from higher level to lower level. In liquids, the particles are slightly loosely packed. As a result, the particles can move, slip and slide past each other.
What are the properties of gases (Third states of matter)?
Gases possess the following properties:
- Gases have no definite shape and no fixed volume. Gases fill the entire space available to them. This is because in gases, the cohesive force between the particles is negligible and these are free to move in any direction.
- Gases are highly compressible. In gases the particles are apart and there is enough space available for compression. Due to high compressibility, a large volume of any gas can be compressed into a cylinder of small volume, and transported easily.
- Gases have very low density. As compared to solids and liquids, gases have very low densities. This is because there is a lot of empty space in gas molecules.
- Gases diffuse into each other rapidly. This is because the particles in gases can freely move in all directions with high speeds, and there is a lot of intermolecular space in gases. The speed of particles in any form of matter increases with a rise in temperature. That’s why difusion become faster on rising the temperature.
- Gases can easily flow from high pressure to low pressure.
- Gases exert pressure on the walls of the container in which it is filled. The gaseous particles move in all direction at a very high speed. The particles in gases collide with each other and with the walls of the container. When these particles strike the wall, they exert force on it. The force exerted per unit area of the wall is called pressure exerted by the gas. Gases exert equal pressure in all directions.
Read More: What factors governs the state of matter?