Based on the force of attraction between the particles, there are three states of matter. By looking at a table, river, and smoke, can you see the difference between them? These objects are classified into solid, liquid, and gas-based on differences in their properties like shape, volume, the intermolecular force of attraction, cohesive forces, and Brownian movement.

Classification of Matter into Solid
In solid matter, like a table, you will observe that it has a fixed shape and volume. It is rigid due to the strong force of attraction between the particles. Due to this strong force, the particles have very little space between them, and they are arranged compactly. Cohesive forces between the particles tend to hold them tightly and are strong in solids. Particles move randomly inside the matter and show Brownian movement. But, in solids, this movement is the least due to the strong forces of attraction.

Classification of Matter into Liquid
Try to pour the water in a spoon, glass, bottle, or bucket. You will notice that water can take the shape of the container. Water being a liquid doesn’t have a specific shape but takes that of the container. It does have a definite volume though. Since liquids can flow, the particles have more space between them and hence weaker force of attraction than solid. Liquids have comparatively less cohesive forces. Brownian movement in the liquid is more than the solid due to the weaker force of attraction.

Classification of Matter into Gases
Fill a balloon with air, and then blow it out. You will see that it seems very light. Gases are the state of matter without any shape or volume. You can easily move your hands past the air. This means that the particles are far from each other. The particles of gases have the weakest force of attraction between them. Gases have weak cohesive forces between the particles. Brownian movement of the particles is highest since due to less force of attraction, they move randomly in the matter.

Take two ice cubes in a pan, keep it still and observe it. After some time, you will observe that ice has melted to form water. Put the pan on the stove to provide heat or bring the pan in sunlight. You will observe that water has vanished. These observations depict the effect of heat on the state of matter.

Evaporation
On providing the heat to solid-state, it changes into a liquid, and on further heating, the liquid state converts into a gaseous state. But why does it happen? Heat is a type of energy and thus leads to change in the state of matter. Particles of solid absorb heat, and they move far from each other and hence convert into a liquid state. On supplying more heat to the liquid, they will further separate out and lead to a decrease in the force of attraction. This will change their state into a gaseous state. Thus, the change of state of matter is due to the heat provided to it.

Condensation
What happens during cloud formation? Small water vapors combine and form clouds, and when the clouds become heavy, they fall on earth as rain. This conversion of gas into liquid is called condensation.

Freezing
Keep a bowl filled with water inside the freezer. You will observe that after some time water converts into ice. This conversion of liquid into solid at decreasing temperature is called freezing.

Expansion
You might have seen that some gaps are left in the railway tracks during summer. Do you know the reason for that? This is due to expansion. While heating matter, particles undergo expansion since they absorb heat energy. They start moving randomly and far from each other, and the force of attraction decreases between them.

Chemical Change
Above mentioned examples were physical changes in the state of matter resulting from heating, but sometimes heating can lead to a chemical change of the matter. You might have observed a burning candle. On burning the candle, melting of wax is a physical change, while burning of wick in the presence of oxygen is a chemical change.

You have learned about matter, state of matter, classification of matter into solid, liquid, gas, and conversion of matter. To know about matter further, you can download the MSVgo app, which offers a large base of learning videos, quizzes, interactive games, and many more to the students till grade 12.