halogênio

Halogênio is a term that refers to the elements in Group 17 of the periodic table. These elements include fluorine, chlorine, bromine, iodine, and astatine. They are characterized by having seven valence electrons, meaning they are just one electron short of achieving a full outer electron shell. This high reactivity makes them eager to gain an electron, often by forming ionic or covalent bonds with other elements.

Fluorine is the most electronegative and reactive element in the entire periodic table. Chlorine is a widely used disinfectant and is a component of table salt. Bromine is a volatile liquid at room temperature and is used in flame retardants and pesticides. Iodine is essential for thyroid hormone production in humans and is also used as an antiseptic. Astatine is a rare and highly radioactive element, and its chemical properties are less well-studied compared to the other halogens.

In their elemental form, halogens typically exist as diatomic molecules, meaning they are composed of two atoms bonded together (e.g., F2, Cl2, Br2, I2). They exhibit a range of physical states at room temperature: fluorine and chlorine are gases, bromine is a liquid, and iodine is a solid. When they react with metals, they form salts, which is where the name "halogen" originates, derived from Greek words meaning "salt-former." Their strong oxidizing properties are a key characteristic and are utilized in various industrial and chemical processes.