halideion

A halide ion is an atom of a halogen element that has gained one electron, resulting in a net negative charge. The halogens are a group of elements in the periodic table consisting of fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). When these elements form ions, they typically achieve a stable electron configuration by gaining a single electron to fill their outermost electron shell. For example, a chlorine atom, which has 7 valence electrons, gains one electron to become a chloride ion (Cl-), with a full outer shell of 8 electrons. Similarly, fluorine forms a fluoride ion (F-), bromine forms a bromide ion (Br-), and iodine forms an iodide ion (I-). Astatine, being radioactive and rare, also forms an astatide ion (At-). These halide ions are important in various chemical and biological processes. They are commonly found in ionic compounds, such as sodium chloride (NaCl), where the sodium ion (Na+) and chloride ion (Cl-) are held together by electrostatic attraction. In biological systems, halide ions like chloride play crucial roles in nerve impulse transmission and maintaining fluid balance.