What are substances?

A substance is like a special kind of building block that everything is made from, just like LEGO bricks.

Imagine you have a big box full of LEGO bricks. Each brick is different: some are red, some are blue, and they come in all shapes and sizes. But no matter which one you pick, it’s still a LEGO brick. That's what a substance is, like a group of similar building blocks that make up things around us.

Think about your favorite juice. It might be apple juice or orange juice. Even though they taste different, each one has its own kind of substance, the stuff that gives it its color and flavor. Apple juice is mostly made from apples, while orange juice is mostly made from oranges.

Now imagine you have a bag of marbles. All the marbles are the same size and shape, but some are green, some are blue. Even though they look different, they're all still marbles, just like how different things can be made from the same kind of substance.