Electrode

Summary: A conductor (usually graphite or metal) through which electric current enters or leaves an electrolyte during electrolysis. Tags: igcse chemistry definition electrolysis Created: 2026-07-14 Last Updated: 2026-07-14

An electrode is a solid electrical conductor — typically made of an inert material such as graphite (carbon) or platinum, though sometimes an active metal — that makes contact with an electrolyte to carry electric current into or out of the circuit during electrolysis. The positive electrode is called the anode, where oxidation takes place (electrons are lost by anions), while the negative electrode is called the cathode, where reduction takes place (electrons are gained by cations). Inert electrodes do not react chemically with the electrolyte or its decomposition products, making them essential for investigating electrolysis without contaminating the results; graphite is preferred industrially because it is cheap and conducts well, while platinum is used when graphite would be unsuitable. For processes such as the electrolysis of brine or the extraction of aluminium, the choice of electrode material significantly affects the efficiency and purity of the products obtained. IGCSE candidates should be able to label the anode and cathode on a diagram, state the products formed at each, and recall the mnemonic ‘AnOx, RedCat’ (Anode = Oxidation, Reduction = Cathode).

Key term — IGCSE Chemistry (0620/0971) glossary.