halogenidiryhmän

Halogenidiryhmä refers to a group of chemical elements known as halogens. These elements are located in Group 17 of the periodic table. The halogens include fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). Tennessine (Ts) is also a synthetic element considered a halogen. They are characterized by having seven electrons in their outermost electron shell, which makes them highly reactive.

In their elemental form, halogens exist as diatomic molecules, meaning they consist of two atoms bonded together (e.g., F₂, Cl₂, Br₂, I₂). They are typically non-metals, with the exception of astatine, which exhibits some metalloid properties. Fluorine is the most electronegative and reactive of all elements. As one moves down the group, their reactivity generally decreases, while their atomic size and boiling points increase.

Halogens readily form compounds with other elements, particularly metals, where they typically gain one electron to achieve a stable electron configuration, forming halide ions. These compounds, known as halides, are common and have diverse applications. For example, sodium chloride (NaCl) is common table salt, and many halogen compounds are used in disinfectants, plastics, and pharmaceuticals. Astatine is radioactive and rare, found in very small quantities in nature.