1:57 (Triple only) know that anion and cation are terms used to refer to negative and positive ions respectively
A negative ion is called an anion. Examples are the bromide ion (Br⁻) and the oxide ion (O²⁻).
A positive ion is called a cation. Examples are the sodium ion (Na⁺) and the aluminium ion (Al³⁺).
A trick to remember this is to write the ‘t’ as a ‘+’ in the word cation: ca+ion