Definition - What does Halogen mean?
Halogens are a group of five related chemical elements found in the periodic table, namely, fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). The term halogen originates from a combination of Greek words meaning salt-producing.
When halogens react with metals, they produce a wide range of salts, such as sodium chloride, calcium fluoride and potassium iodide. As a result of this salt production, halogens are detrimental to some metallic surfaces.
Corrosionpedia explains Halogen
Halogens are the only group in the periodic table that contain elements in all three states of matter at standard temperature and pressure:
- Solid: iodine, astatine
- Liquid: bromine
- Gas: fluorine, chlorine
Most of the salts produced by halogens when they react with metals are soluble in water, making them ideal components for potent electrolytes. Halogens, therefore, have the potential to create optimal conditions for corrosion and chemical attack.
Fluorine in particular is highly aggressive and considered to be one of the most reactive halogen elements. Its reactivity is such that if it is stored in a container constructed from a relatively inert material, such as glass, it can react to form small amounts of water to produce silicon tetrafluoride.