Introduction 

The matter refers to anything that occupies space and has mass, and the universe is made of matter: air, water, food, seas, and airplanes. All of these things essentially matter. Matter is made of particles. Rock, air, and water look different, but they have one big thing in common: they are all made of very tiny pieces, far too small to see. These pieces are called particles.

The Movement of Particles 

In rock and other solids, the particles are not free to move around, but in liquids and gases, they move freely. The particle in liquid or gas moves in a random way, changing direction every time it hits another particle. It is called random motion. An example: cooking smells can spread into the street. This is because ‘smells’ are caused by gas particles mixing with, and moving through, the air.

States of Matter 

There are three states: solid, liquid, and gas. A solid has a fixed shape and a fixed volume. It does not flow, like all the solid things around us; their shapes and volumes do not change. A liquid flows easily; it has a fixed volume, but its shape changes. It takes the shape of the container you pour it into. A gas does not have a fixed volume or shape. It spread out to fill its container. It is much lighter than the same volume of solid or liquid. An example of this is water. Water can be a solid (ice), a liquid (water), and a gas (water vapour or steam). Its state can be changed by heating or cooling. Ice slowly changes to water when it is put in a warm place. This change is called melting. The temperature shows 0°C until all the ice has melted, so 0°C is called its melting point.

How are the Particles Arranged?

The particles in a solid are arranged in a fixed pattern on the lattice. Strong forces hold them together. So, they cannot leave their positions. The only movements they make are tiny vibrations to and from. When the water is heated, its temperature rises, and some of it changes to water vapour. This change is called evaporation; the water gets, the more quickly it evaporates. The particles in a liquid can move about and slide past each other. They are still close together, but not in a lattice. The forces that hold them together are weaker than in a solid. Soon bubbles appear in the water. It is boiling. The water vapour shows up as steam, the temperature stays at 100 °C while the water boils off. 100 °C is the boiling point.

Changing States Are Melting

When a solid is heated, its particles get more energy and vibrate more. The solid turns liquid, boiling when a liquid is heated, its particles get more energy and move faster, which makes the liquid expand through evaporation. Particles in a liquid have more energy than others. This is called evaporation. 

Conclusion

Everything around us is matter, which consists of particles, and the matter has three states: solid, liquid, and gas. These states are changing between each other.