Matter

Everything we see and use in our daily life is 'matter'. Matter is anything that has mass and occupies space. Substance which can be calculated or estimated by either (i) volume, (ii) mass, or combination of these

variables is called as matter.

OR

"Matter is an entity which occupies space and has mass".

Matter is classified on the basis of its physical properties and chemical nature.

Physical properties
1. Matter is made up of partical s. Every matter is composed of several similar repeating units called particles.

The nature particles and physical forces among them determine the nature of the matter. Every particle of matter is bonded to other particles due to the attractive forces among them. Every particle of matter has its own energy to move, For example, when we dissolve salt in water, the particles of salt get into the spaces between particles of water.

2. Particles of matter have space between them Every matter of different states is formed by the union of a number of constituting particles which possess interstitial spaces between them. This space may vary in different matters because of the different arrangements and the nature of particles.

The space between two neighbouring particle units is known as interstitial space.

3. Partical of matter move continuously. If you put a drop of ink into water and keep it undisturbed for some time, you will find later on that ink has spread throughout the water. This is because the particles of ink keep on moving. So, the particles of matter move continuously. Their movement depends upon the nature of matter, the

physical forces operating between them and the kinetic energy of the particles,

For example, when some crystals of copper sulphate are added to a beaker containing hot water and some of its crystals to another beaker containing cold water, it is observed that rate of mixing of copper sulphate is higher in hot water than in cold water because the kinetic energy of particles increases with the increase in temperature.

4. Particles of matter attract each other

All the material looks united and constructed because their constituting particles are assembled. A question arises that why particles assemble together? The answer is attractive force. Every particle of matter exerts an attractive force on its neighbouring particles and hence they assemble together. Efficiency of these forces vary for the different type of materials. These forces also predict the size and the shape of the material.

5. Particles of matter are very small

If you put a drop of blue ink into 500 mL water, the colour of water will turn blue. Again take a drop of this solution and put it in another 500 mL water. Again the water will turn blue (however the blue colour fades). This shows that a drop of ink contains millions of particles which in turn shows that the particles of matter are very small.