halogénatom

A halogénatom, or halogen atom, refers to an atom belonging to Group 17 of the periodic table. These elements are fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). They are characterized by having seven electrons in their outermost electron shell, making them highly electronegative and reactive. Their electronic configuration is typically ns²np⁵, where 'n' represents the principal energy level.

Due to their nearly complete valence shell, halogen atoms readily gain one electron to achieve a stable electron configuration, typically forming a halide ion with a charge of -1. This tendency makes them strong oxidizing agents. In chemical reactions, they often form ionic bonds with metals and covalent bonds with nonmetals.

The reactivity of halogens decreases down the group, with fluorine being the most reactive and astatine the least. Fluorine, being the most electronegative element, readily reacts with almost all other elements. Chlorine is also highly reactive and is used in various industrial processes, including water purification and the production of plastics. Bromine and iodine are less reactive but still significant in chemical synthesis and biological processes, such as the production of thyroid hormones by iodine. Astatine is a rare and radioactive element, and its chemical properties are less extensively studied. Halogen atoms are essential components of many organic and inorganic compounds.