Halogeenrühmad

Halogeenrühmad, often referred to as halogens, are a group of five elements found in Group 17 of the periodic table. These elements are fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). They are characterized by their high reactivity and tendency to gain one electron to form a stable, negatively charged ion with a charge of -1. This electron affinity makes them strong oxidizing agents.

In their elemental form, halogens exist as diatomic molecules, meaning they consist of two atoms bonded together (e.g., F₂, Cl₂, Br₂, I₂). Their physical properties vary significantly with atomic number. Fluorine is a pale yellow gas, chlorine is a greenish-yellow gas, bromine is a reddish-brown liquid, and iodine is a dark purple solid that sublimes to a violet vapor. Astatine is a rare and radioactive element, and its properties are less well-understood.

Halogens readily react with many other elements, including metals and nonmetals. They form ionic compounds with metals, such as sodium chloride (NaCl), and covalent compounds with nonmetals, like hydrogen chloride (HCl). These compounds are often referred to as halides. Due to their reactivity, halogens and their compounds have numerous industrial and commercial applications, including disinfectants, plastics, pharmaceuticals, and photography. However, many halogens are also toxic and require careful handling.