The balanced chemical equation is the standard way to communicate chemical information but it is only useful if you understand what it means. The best way to do this is to try to see it as a story told in code rather than as a list of symbols.

We can start off by looking at a few chemical equations and “translating” them into words. After all, we think in words so this might make it easier.

CaCO₃ → CaO + CO₂

At a basic level: Calcium carbonate breaks down to give calcium oxide and carbon dioxide.

Slightly more advanced: One mole of calcium carbonate breaks down to give one mole of calcium oxide and one mole of carbon dioxide. This gives information that is useful to show how much of each chemical reacts and how much is produced. It allows us to link these bits of information in order to do calculations.

2Mg + O₂ → 2MgO

At a basic level: Magnesium reacts with oxygen to make magnesium oxide.

Slightly more advanced: Two moles of magnesium atoms react with one mole of oxygen molecules to form one mole of magnesium oxide.

The 2Mg (big and in front of Mg) means “two moles of magnesium”.

The O₂ (small and after the O) means that each molecule of oxygen is made of two oxygen atoms joined together.

2O and O₂ both contain the same number of O atoms but in O₂ we are showing that the atoms are in pairs while in 2O they are in singles.

You can think of this in terms of a box of six eggs, it could have the formula E6.
Six eggs on their own would be 6E.