What do you think you're made of?
You are made up of lots of different parts, but if we think even smaller we can conclude that every single part of you is actually made of atoms! In fact, everything in the universe is made of atoms.
Atoms are the simplest particle of an element. Different things are made of different types of atoms. A piece of gold for example is made up of lots of gold atoms. Oxygen is made up of oxygen atoms.
We can't see individual atoms with the human eye as they are just so small. Only the most powerful microscopes can see them.
Atoms have a radius of about one nanometre. It's hard to think about what this actually means ...... so look at a centimetre on a ruler. How many atoms do you think would need to be lined up in a row to stretch that centimetre?
Ready for it.......... 100,000,000!
Because we can't easily see atoms (without the use of a very powerful microscope!) we can represent atoms as small balls, and when we draw them we often just draw small circles. Each small circle would represent a single atom.
All atoms of the same type would be drawn as the same size and colour circle. Atoms from different elements would be drawn as different colours, and maybe even different sizes. Atoms of the same type can be joined together if it's just a single element, or joined in pairs if it's a molecule of an element, and atoms of different types can join together to form compounds. But remembering that atoms of the same type are all drawn as the same colour, you can easily determine if a picture of a molecule shows just one type of atom or many.
Let's have a look at this in some more detail!