Understand How to Represent Atoms in Chemical Reactions

Compounds are chemical substances that contain more than one element. They're created during a chemical reaction where atoms are rearranged into new compound molecules.

Atoms are the simplest and smallest things that exist. 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. So because we can't easily see atoms (without the use of a very powerful microscope!) we can picture 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. So you can easily determine if a picture of a molecule shows just one type of atom or many. 

In a chemical reaction, we can draw what is happening to the atoms. As you can see below there are two different types of atoms involved in this chemical reaction - blue ones are oxygen, and red ones are carbon. It shows the formation of carbon dioxide.

Ready to try some questions on atoms in chemical reactions? Great, let's go!