Halogeenrühmade

Halogeenrühmade, commonly known as halogens, refers to a group of elements in the periodic table, specifically Group 17. This group consists of fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). These elements are highly reactive due to their electron configuration, possessing seven valence electrons and needing only one more electron to achieve a stable noble gas configuration. This tendency makes them strong oxidizing agents.

In their elemental form, halogens exist as diatomic molecules (e.g., F2, Cl2). Their physical properties vary across the group; fluorine and chlorine are gases at room temperature, bromine is a liquid, and iodine and astatine are solids. Reactivity generally decreases down the group, with fluorine being the most reactive and astatine the least.

Halogens readily form ionic and covalent compounds. They combine with metals to form salts, hence the name "halogen" which derives from Greek words meaning "salt-former." For example, sodium chloride (NaCl), common table salt, is a compound formed between sodium and chlorine. They also form many covalent compounds with nonmetals, such as hydrogen halides (e.g., HCl, HBr), which are often acidic in aqueous solution. The properties and applications of halogen compounds are diverse, ranging from disinfectants and bleaching agents (chlorine) to refrigerants and plastics (fluorine compounds). Astatine is a rare radioactive element with limited applications, primarily in research.