Tiny Particles You Cannot See

You will be able to show that matter is made of particles that are far too small to see.

Think about blowing up a balloon at a birthday party in Texas. Before you blow, the balloon is flat and floppy. After you blow, it is round and firm. Nothing you can see went inside, but something did. Air went in. Air is matter, which means it is anything that takes up space and has mass.

Air is made of particles. Particles are tiny pieces of matter that are much too small to see, even with a regular magnifying glass. Millions and millions of them are moving around inside that balloon right now. They bump into the walls of the balloon over and over. All those tiny bumps push the rubber out and keep the balloon puffed up.

You can find clues about particles in other places too. When someone opens a bag of popcorn in the kitchen, you smell it from the next room. Tiny particles from the popcorn spread through the air and reach your nose. You never see them travel, but you know they arrived. When you let go of an untied balloon, it zips across the room because the particles rush out fast.

Here is a good way to picture it. Imagine a huge jar filled with grains of sand. From far away, the sand looks like one smooth thing. Up close, you see it is made of many separate grains. Matter works in a similar way, except the particles are so small that you cannot see even one of them. Solids, liquids, and gases are all made of these tiny particles.

Try it: If a balloon full of air feels light but still has mass, what does that tell you about the particles inside it?