UNIT OVERVIEW

This unit covers redox reactions—chemical reactions that involve the transfer of electrons between substances. The name "redox" comes from reduction and oxidation happening at the same time.

Many everyday processes involve redox reactions: rusting, batteries, burning fuels, and even breathing. Understanding redox helps you explain these processes at the atomic level.

By the end of this unit, you will be able to:

• Define oxidation and reduction in terms of electron transfer
• Assign oxidation numbers to atoms in molecules and ions
• Apply rules for determining oxidation numbers
• Identify which species is oxidised and which is reduced in any reaction
• Recognise oxidising agents and reducing agents
• Balance redox equations using the oxidation number method