Matter is made of particles. Let us do two simple experiments to understand the characteristics of these particles and how do they decide the nature of matter.

Take about 50 ml water in a beaker. Take about half a spoon of common salt. Put the salt into water and stir the solution. What do you observe? Before mixing, salt and water were two different substances. Salt was in solid state and water was in liquid state. After mixing, what happened to the salt ? Where did it disappear ? Did the level of water in the beaker change ? In order to answer these questions, we need to use the idea that matter is made of particles. The particles of solid salt got spread throughout water and they became invisible. This suggests that particles of one type of matter get into the spaces between particles of the other. This shows that there is enough space between particles of matter.

Let us think of a game played on play-ground. Make four groups of students and form their human chains as suggested. The first group should hold each other from the back and lock arms like Bihu dancers. The second group should hold hands to form a human chain. The third group should form a chain by touching each other with only their finger tips. The fourth group should try to break the three human chains one by one into as many small groups as possible. Which group was the easiest to break? Why? If we consider each student as a particle of matter, then in which group the particles held each other with he maximum force ? This experiment suggests that particles of matter have force acing between hem. This force keeps the particles together. The strength of this force of attraction varies form one kind of matter to another.

Matter is made up of very tiny particles called atoms or molecules which have spaces between them . Some force of attraction holds these tiny particles together in the matter.