When we look around us, we observe a wide range of shapes, sizes, and materials. According to researchers, “matter” makes up everything in the universe. The water we drink, sand, air, mountains, plants, animals, or a grain of sand are all ‘matter.’ When we look around, we can see that all of the objects mentioned above take up space and have mass. Classification based on physical state is determined by physical characteristics of matter. 

What is Matter?

The term “matter” means that it has some mass and covers space. Any material is made up of millions of tiny particles. To the naked eye, these particles are invisible. The physical and chemical natures of matter are used to classify it. We have three classification based on their physical states: Solids, Liquids, and Gases. There is a force existing between matter particles. The particles are held together by this force. The degree of this attraction varies depending on the type of substance.

Classification Based on Physical State

The matter is classified into three categories based on its physical characteristics: solid state, liquid state and gaseous state 

Solid state

• Solids are a type of matter with a hard structure that resists changes in shape and volume. They have securely packed particles that are well-arranged in a regular pattern. Its particles will continuously vibrate and twist, but they will not show any motion since they are firmly bound together.
• They have stable forms and have the strongest intermolecular interaction. Furthermore, compression is exceedingly difficult because their molecules have relatively few gaps between them. When exposed to external stress, solids tend to keep their form. Solids are breakable, but their shape cannot be changed. Hence they are resistant.
• Examples: Whether we hold a sugar or salt crystal in our hand, place it on a plate, or place it in a container, its form stays constant. A sponge has tiny pores in which air is trapped; when we push it, the air escapes, and we may compress it. 
• A solid can transform into a liquid through melting, and through freezing, a liquid can be converted into a solid. Sublimation is a process that allows a solid to transform into a gas.

Liquid state

• Liquids are substances that flow freely. They are of a constant volume and have no distinct form. As a result, they acquire the shape of the container in which they are contained. Intermolecular connections bind the little particles in them together firmly. Liquids have a small surface area due to their surface tension. Liquids move and alter form, making them fluid rather than stiff.
• Solids and liquids can both diffuse into liquids. Gases from the atmosphere permeate into the water and disintegrate. Gases like oxygen and carbon dioxide are required for marine animals and plants to survive. All living things require oxygen to survive. The presence of dissolved oxygen in water allows marine species to breathe underwater. As a result, liquids and gases may all permeate into liquids. The rate of liquid diffusion is quicker than the rate of solid diffusion. Due to this, particles in the liquid state are free to move around and have more space than particles in the solid state.
• A liquid can be turned into a gas by heating it to its boiling point or lowering the pressure at a constant temperature. The change of a matter from a liquid state into a gaseous state is referred to as evaporation.

Gaseous state

• Gas is a condition of matter that may distribute freely in all directions. As a result, they occupy the available area, regardless of quantity. The particles it contains aren’t uniform in size or shape. Their molecules are loosely bound together, leaving plenty of room for them to move about freely and continuously.
• In comparison to solids and liquids, gases are very compressible. Compressed gas is the liquefied petroleum gas (LPG) cylinder we get at home for cooking or the oxygen delivered in cylinders to hospitals. Compressed natural gas (CNG) is employed as a fuel in today’s cars. Large amounts of gas may be compressed into a tiny cylinder and carried easily due to its great compressibility.
• The particles in the gaseous state move about at a high rate randomly. Because of this random movement, the particles collide with each other and the container’s walls. The gas exerts pressure on the container walls because of this force exerted by gas particles per unit area on the container walls.

Conclusion 

The materials in our environment exist in three states: solid, liquid, and gas. Classification based on its physical state can be distinguished from each other by its appearance and physical properties. Solids have the strongest attraction forces; liquids have intermediate strengths, and gases are the weakest. Solids have the smallest gaps between component particles, liquids have medium spacing, and gases have the largest spaces and kinetic energy. Solids have the most organised particle arrangement, whereas liquids have layers of particles that can slip and slide over each other. On the other hand, Gases have no order, and particles move around at random. Plasma and Bose-Einstein Condensate are the two additional states of matter; however, solid, liquid, and gas are the most prevalent states of matter.