Chemical substance

A chemical substance is something made up of very tiny things called molecules. Imagine you have a bunch of little toy blocks, each with a different shape and size. If you put them all together in a certain way, you can make something like a house or a car. Chemical substances are kind of like that - scientists use different molecules to make up different substances.

Some substances are good for us, like the oxygen we breathe in or the water we drink. Other substances can be dangerous or harmful if we eat them or breathe them in, like bleach or gasoline. Scientists study chemical substances to understand how we can use them safely, and how we can protect ourselves from substances that might hurt us.

Chemical substances are all around us - in the air we breathe, the food we eat, the clothes we wear, and the medicine we take. We need some chemical substances to live, but we have to be careful with others. Scientists work hard to make sure we understand chemicals and use them safely.