In chemistry, a halide refers to a chemical compound containing one or more halogen atoms bonded to another element. The halogens are a group of elements in the periodic table that includes fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At).
Halides can form ionic or covalent compounds depending on the nature of the bonding between the halogen atom and the other element. Ionic halides typically involve a halogen atom gaining an electron to form a negatively charged ion (anion), while the other element becomes a positively charged ion (cation). Covalent halides, on the other hand, involve sharing electrons between the halogen and the other element to form a molecular compound.
Halides are widely used in various chemical reactions, industrial processes, and applications. For example, sodium chloride (NaCl) is a common ionic halide known as table salt, while hydrogen chloride (HCl) is a covalent halide used in the production of various chemicals. Halides also play important roles in biological systems, such as in the formation of hydrochloric acid in the stomach and in the synthesis of thyroid hormones containing iodine.