# Matter

All the objects around us - tables, chairs, paper, steel, water, ice, etc., are matter. Matter is anything that has mass and occupies space. Matter appears in a huge variety of forms.

Activity 1
Fill a bowl with water. Hold a glass tumbler upside-down above the water and push it slowly into the water. It does not go in easily. Now hold the tumbler, still upside-down, at the bottom of the bowl. The water is still unable to enter the tumbler. If you tilt the tumbler, you will see bubbles coming out.

Question

What does it show?

Solution

This shows that matter occupies space. Even air, that we cannot see, fills up the space inside the container, takes up its shape, and prevents the water from entering the tumbler.

Activity 2
To show that particles of matter are very small
Take 2-3 crystals of Copper Sulphate and dissolve them in 100 ml of water. Take out approximately 10 ml of this solution and put it into 90 ml of clear water. Take out 10 ml of this solution and put it into another 90 ml of clear water. Keep diluting the solution like this 5 to 8 times.

Question

Is the water still coloured?

Solution

Estimating how small the particles of matter are: with every dilution, though the blue colour becomes light, it is still visible. This experiment shows that just a few crystals of copper sulphate can colour a large volume of water (about 1000 L). So we conclude that there must be millions of tiny particles in just one crystal of copper sulphate, which keep on dividing themselves into smaller and smaller particles. Ultimately a stage is reached when the particles cannot divide further into smaller particles.

Activity 3
To show that particles of matter are continuously moving Place a few drops of liquid bromine in a gas jar. You will see brown fumes of bromine rise up in the gas jar. Since bromine gas is heavier than air, it should have remained at the bottom of the gas jar. Why do the fumes rise up?

Because of the random motion of the bromine molecules, they diffuse into the air molecules. Therefore we see brown fumes rising up in the gas jar due to diffusion. In fact, if we place an inverted gas jar on top of this gas jar, the brown fumes would fill the inverted gas jar too.

Question

What would happen if we placed this gas jar in a vessel containing hot water?

Solution
The bromine vapour will diffuse into the water vapour. When the water vapour eventually condenses, the colour of the water will be brown indicating that bromine has dissolved in water. In this way, bromine dissolves in water through diffusion.

People have speculated for centuries about how matter is made up. Ancient Indian and Greek philosophers thought that the wide variety of objects around us results from an appropriate combination of five basic 'elements', namely, earth, fire, water, air and sky. The entire universe was thought to be made of these elements. The elements could undergo transformation into different substances depending upon their primary qualities. The great sage Kanada (about 600 B.C.) had proposed that matter consists of eternal and imperceptible parmanus which when combined in diads, triads, etc., form matter. Thus, parmanus are the ultimate cause of the universe.

An Athenian philosopher, Democritus had a similar idea. He taught in about 400 B.C. that the world was made up of tiny particles. He described these as imperceptible (unable to be perceived by the senses), indivisible and indestructible. This idea of tiny particles being the building blocks of all matter reappeared from time to time but did not gain general acceptance until the nineteenth century.

Matter can be grouped in a number of ways. However, in modern science there are two principal ways of grouping matter:

1) by its physical state as a solid, liquid, or gas, and

2) by its chemical constitution as an element, compound or mixture.