Break it, and break it again

The idea

Matter is composed of a large number of extremely small constituent particles, the basic units that make up a substance, too small to be seen even through an ordinary microscope.

Pebbles and sand

Rivers break rocks into pebbles, stones and sand. In the end, rocks become fine grains of sand and clay.

Is a grain of sand the smallest unit of a rock?

• No, it is made of even smaller units
• Yes, nothing can be smaller than a grain of sand
• Yes, a grain of sand can never be broken

Keep breaking

Break the chalk, the rock and the sugar again and again. How far can you go?

Constituent particles

Matter is composed of a large number of extremely small particles. A constituent particle is the basic unit that makes up a substance. These particles are so small that they cannot be seen even through an ordinary microscope.

Long ago, Acharya Kanad, an ancient Indian philosopher, said that matter is made up of tiny, indivisible, eternal particles called Parmanu (atom). He wrote this in his work, the Vaisheshika Sutras.

• What we broke | What it is made of
• A piece of chalk | Constituent particles of chalk
• A rock (its sand and clay grains) | Constituent particles
• A grain of sugar | Millions and millions of constituent particles

Notes

Matter is made of a large number of extremely small constituent particles: the basic units of a substance, too small to be seen even through an ordinary microscope.

Check yourself

What is a constituent particle?

Can you see the constituent particles of chalk through an ordinary microscope?

Sugar dissolves in water and can no longer be seen. How do we know it is still there?

News about air pollution talks about tiny dust particles in the air. Is a dust particle a constituent particle?

• A grain of sand. A grain of sand is itself made of a large number of constituent particles.
• The basic unit that makes up a substance — correct. Yes. It cannot be broken down any further.
• A speck of chalk powder. A speck can still be broken into smaller particles, so it is not the basic unit.
• Yes, if the chalk is ground for a long time. Grinding does not make the particles bigger. They stay too small to be seen.
• Yes, as tiny white dots. Tiny white dots are specks of powder, each made of a huge number of particles.
• No. They are too small to be seen even through an ordinary microscope — correct. Right. They are extremely small.
• The water tastes sweet — correct. Yes. The sugar broke up into tiny particles that are still in the water.
• We cannot know; it is gone. The water tastes sweet, so the sugar is still there, as tiny particles.
• It has turned into water. Sugar does not turn into water. The sweet taste shows that sugar is still present.
• Yes. Dust particles are the smallest particles. Constituent particles are extremely small compared with dust particles.
• No. Each dust particle is made of a very large number of constituent particles — correct. Right. The word 'particle' means different things in different contexts.
• Yes, because it floats in the air. Floating does not make it a constituent particle. A dust particle is made of very many of them.