Halide Ion - GCSE Chemistry Definition

A halide ion is a type of negatively charged particle that forms when a halogen atom gains an extra electron. Halogens are a group of elements found in Group 7 of the periodic table, which include fluorine, chlorine, bromine, iodine, and astatine. When these elements gain an electron during chemical reactions, they become charged ions known as halide ions. For example, if chlorine gains an electron, it becomes a chloride ion (Cl⁻). This half equation shows the formation of this ion: Cl + e⁻ → Cl⁻. Halide ions are important in many chemical reactions and are commonly found in salts, like sodium chloride (table salt), and in various other compounds used in everyday life.