Halogen

  • halogens
    hydrogen helium
    lithium beryllium boron carbon nitrogen oxygen fluorine neon
    sodium magnesium aluminium silicon phosphorus sulfur chlorine argon
    potassium calcium scandium titanium vanadium chromium manganese iron cobalt nickel copper zinc gallium germanium arsenic selenium bromine krypton
    rubidium strontium yttrium zirconium niobium molybdenum technetium ruthenium rhodium palladium silver cadmium indium tin antimony tellurium iodine xenon
    caesium barium lanthanum cerium praseodymium neodymium promethium samarium europium gadolinium terbium dysprosium holmium erbium thulium ytterbium lutetium hafnium tantalum tungsten rhenium osmium iridium platinum gold mercury (element) thallium lead bismuth polonium astatine radon
    francium radium actinium thorium protactinium uranium neptunium plutonium americium curium berkelium californium einsteinium fermium mendelevium nobelium lawrencium rutherfordium dubnium seaborgium bohrium hassium meitnerium darmstadtium roentgenium copernicium nihonium flerovium moscovium livermorium tennessine oganesson
    chalcogens  noble gases
    iupac group number 17
    name by element fluorine group
    trivial name halogens
    cas group number
    (us, pattern a-b-a)
    viia
    old iupac number
    (europe, pattern a-b)
    viib

    ↓ period
    2
    image: liquid fluorine at cryogenic temperatures
    halogen
    3
    image: chlorine gas
    halogen
    4
    image: liquid bromine
    halogen
    5
    image: iodine crystal
    halogen
    6 halogen
    7 halogen

    legend

    primordial element
    element from decay
    atomic number color:
    black=solid, green=liquid, red=gas

    the halogens (n/[1][2][3]) are a group in the periodic table consisting of five chemically related elements: fluorine (f), chlorine (cl), bromine (br), iodine (i), and astatine (at). the artificially created element 117, tennessine (ts), may also be a halogen. in the modern iupac nomenclature, this group is known as group 17.

    the name "halogen" means "salt-producing". when halogens react with metals, they produce a wide range of salts, including calcium fluoride, sodium chloride (common table salt), silver bromide and potassium iodide.

    the group of halogens is the only periodic table group that contains elements in three of the main states of matter at standard temperature and pressure. all of the halogens form acids when bonded to hydrogen. most halogens are typically produced from minerals or salts. the middle halogens—chlorine, bromine, and iodine—are often used as disinfectants. organobromides are the most important class of flame retardants, while elemental halogens are dangerous and can be lethally toxic.

  • history
  • characteristics
  • production
  • applications
  • biological role
  • toxicity
  • superhalogen
  • see also
  • notes
  • references
  • further reading

Halogens
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson
chalcogens  noble gases
IUPAC group number 17
Name by element fluorine group
Trivial name halogens
CAS group number
(US, pattern A-B-A)
VIIA
old IUPAC number
(Europe, pattern A-B)
VIIB

↓ Period
2
Image: Liquid fluorine at cryogenic temperatures
Halogen
3
Image: Chlorine gas
Halogen
4
Image: Liquid bromine
Halogen
5
Image: Iodine crystal
Halogen
6 Halogen
7 Halogen

Legend

primordial element
element from decay
Atomic number color:
black=solid, green=liquid, red=gas

The halogens (n/[1][2][3]) are a group in the periodic table consisting of five chemically related elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). The artificially created element 117, tennessine (Ts), may also be a halogen. In the modern IUPAC nomenclature, this group is known as group 17.

The name "halogen" means "salt-producing". When halogens react with metals, they produce a wide range of salts, including calcium fluoride, sodium chloride (common table salt), silver bromide and potassium iodide.

The group of halogens is the only periodic table group that contains elements in three of the main states of matter at standard temperature and pressure. All of the halogens form acids when bonded to hydrogen. Most halogens are typically produced from minerals or salts. The middle halogens—chlorine, bromine, and iodine—are often used as disinfectants. Organobromides are the most important class of flame retardants, while elemental halogens are dangerous and can be lethally toxic.