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MATTER IS MADE UP OF PARTICLES
MATTER IS MADE UP OF PARTICLES
For a long time, two schools of thought prevailed regarding the nature of matter. One school believed matter to be continuous like a block of wood, whereas, the other thought that matter was made up of particles like sand. Let us perform an activity to decide about the nature of matter – is it continuous or particulate?
Activity 1.1: ( Space between particles of Matter )
* Take a 100 mL beaker.
* Fill half the beaker with water and mark the level of water.
* Dissolve some salt/ sugar with the help of a glass rod.
* Observe any change in water level.
* What do you think has happened to the salt?
* Where does it disappear?
* Does the level of water change?
Figure 1.1: When we dissolve salt in water, the particles of salt get into the spaces between particles of water.
In order to answer these questions, we need to use the idea that matter is made up of particles. What was there in the spoon, salt or sugar, has now spread throughout the water. This is illustrated in Fig. 1.1.
Source: This topic is taken from NCERT TEXTBOOK
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HOW SMALL ARE THESE PARTICLES OF MATTER?
HOW SMALL ARE THESE PARTICLES OF MATTER?
Activity 1.2: ( Particles of matter are small )
* Take 2-3 crystals of potassium permanganate 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.
* Is the water still coloured?
Figure 1.2: Estimating how small are the particles of matter. With every dilution, though the colour becomes light, it is still visible.
This experiment shows that just a few crystals of potassium permanganate 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 potassium permanganate, which keep on dividing themselves into smaller and smaller particles.
The same activity can be done using 2mL of Dettol instead of potassium permanganate. The smell can be detected even on repeated dilution.
Note:
The particles of matter are very small – they are small beyond our imagination!!!!
Source: This topic is taken from NCERT TEXTBOOK