Class 9 Science (CBSE)

Matter in Our Surroundings

Is a shadow made of the same stuff as a bucket of water? To find out, we have to look closely at what actually makes up our universe.

Scientists define matter by two simple rules. It must have mass, and it must occupy space, which we call volume.

So, while water has mass and takes up space, light and shadows do not. They are forms of energy, not matter.

But here is the strange part: if you look incredibly close, matter isn't continuous. It is made of tiny, individual particles.

How tiny are they? If you dissolve a single crystal of potassium permanganate in water, it can color thousands of liters.

These particles have spaces between them, they constantly move, and they attract each other. Let's see this in action.

When you dissolve sugar in water, the sugar particles fit perfectly into the empty spaces between the water particles. The water level doesn't even rise!

Depending on how tightly these particles cling together, matter exists in three primary states: solid, liquid, or gas.

A common mistake is thinking that particles change size when heating up. They don't! They just move faster and push further apart.

Remember: matter is anything with mass and volume, built from tiny particles in constant motion. Next time you feel a breeze, you are feeling trillions of those tiny dancers!