KS3 & KS4 science curriculum

This unit builds on pupils’ prior learning from Using Earth's resources, where they explored how natural resources are extracted and processed. It deepens their understanding by focusing on Electrolysis, a key method for extracting and purifying substances, such as metals, through electrical currents. As the final unit in the big question, How can substances be made and changed?, it reinforces pupils’ understanding of how chemical processes transform raw materials into useful products, highlighting the importance of these changes in industry and everyday life.

1. Principles of electrolysis
2. Electrolysis of molten salts
3. Electrolysis: extracting aluminium
4. Electrolysis of aqueous solutions
5. Electrolysis: brine
6. Electrolysis: aqueous solutions practical
7. Electrolysis: purifying copper
8. Half equations: electrolysis
9. Electric cells and batteries
10. Fuel cells

• A chemical that is oxidised either gains oxygen or loses electrons.
• A chemical that is reduced either loses oxygen or gains electrons.
• A redox reaction is one in which both oxidation and reduction take place.
• Redox reactions may be viewed in terms of gain or loss of oxygen or hydrogen, but also gain and loss of electrons.
• Carbon can be used to extract some metals (e.g. iron and copper) from their ores, e.g. copper oxide plus carbon makes copper and carbon dioxide.
• Hydrogen used in fuel cells can be extracted from fossil fuels or produced by electrolysis powered by the national grid.
• During chemical reactions atomic nuclei and electrons are rearranged and new substances are formed.