Chalcogen

  • chalcogens
    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
    pnictogens  halogens
    iupac group number 16
    name by element oxygen group
    trivial name chalcogens
    cas group number
    (us, pattern a-b-a)
    via
    old iupac number
    (europe, pattern a-b)
    vib

    ↓ period
    2
    image: oxygen
    oxygen (o)
    8 reactive nonmetal
    3
    image: sulfur
    sulfur (s)
    16 reactive nonmetal
    4
    image: 2 allotropes of selenium: black and red. 3 others not shown.
    selenium (se)
    34 reactive nonmetal
    5
    image: tellurium in metallic form
    tellurium (te)
    52 metalloid
    6 polonium (po)
    84 post-transition metal
    7 livermorium (lv)
    116 unknown chemical properties

    legend

    primordial element
    naturally occurring by radioactive decay
    synthetic element
    atomic number color:
    red=gasblack=solid

    the chalcogens (z/) are the chemical elements in group 16 of the periodic table. this group is also known as the oxygen family. it consists of the elements oxygen (o), sulfur (s), selenium (se), tellurium (te), and the radioactive element polonium (po). the chemically uncharacterized synthetic element livermorium (lv) is predicted to be a chalcogen as well.[1] often, oxygen is treated separately from the other chalcogens, sometimes even excluded from the scope of the term "chalcogen" altogether, due to its very different chemical behavior from sulfur, selenium, tellurium, and polonium. the word "chalcogen" is derived from a combination of the greek word khalkόs (χαλκός) principally meaning copper (the term was also used for bronze/brass, any metal in the poetic sense, ore or coin),[2] and the latinised greek word genēs, meaning born or produced.[3][4]

    sulfur has been known since antiquity, and oxygen was recognized as an element in the 18th century. selenium, tellurium and polonium were discovered in the 19th century, and livermorium in 2000. all of the chalcogens have six valence electrons, leaving them two electrons short of a full outer shell. their most common oxidation states are −2, +2, +4, and +6. they have relatively low atomic radii, especially the lighter ones.[5]

    lighter chalcogens are typically nontoxic in their elemental form, and are often critical to life, while the heavier chalcogens are typically toxic.[1] all of the naturally occurring chalcogens have some role in biological functions, either as a nutrient or a toxin. selenium is an important nutrient but is also commonly toxic.[6] tellurium often has unpleasant effects (although some organisms can use it), and polonium is always extremely harmful, both in its chemical toxicity and its radioactivity.

    sulfur has more than 20 allotropes, oxygen has nine, selenium has at least five, polonium has two, and only one crystal structure of tellurium has so far been discovered. there are numerous organic chalcogen compounds. not counting oxygen, organic sulfur compounds are generally the most common, followed by organic selenium compounds and organic tellurium compounds. this trend also occurs with chalcogen pnictides and compounds containing chalcogens and carbon group elements.

    oxygen is generally obtained by separation of air into nitrogen and oxygen. sulfur is extracted from oil and natural gas. selenium and tellurium are produced as byproducts of copper refining. polonium and livermorium are most available in particle accelerators. the primary use of elemental oxygen is in steelmaking. sulfur is mostly converted into sulfuric acid, which is heavily used in the chemical industry.[6] selenium's most common application is glassmaking. tellurium compounds are mostly used in optical disks, electronic devices, and solar cells. some of polonium's applications are due to its radioactivity.[1]

  • properties
  • compounds
  • history
  • occurrence
  • production
  • applications
  • biological role
  • toxicity
  • see also
  • references
  • external links

Chalcogens
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
pnictogens  halogens
IUPAC group number 16
Name by element oxygen group
Trivial name chalcogens
CAS group number
(US, pattern A-B-A)
VIA
old IUPAC number
(Europe, pattern A-B)
VIB

↓ Period
2
Image: Oxygen
Oxygen (O)
8 Reactive nonmetal
3
Image: Sulfur
Sulfur (S)
16 Reactive nonmetal
4
Image: 2 allotropes of selenium: black and red. 3 others not shown.
Selenium (Se)
34 Reactive nonmetal
5
Image: Tellurium in metallic form
Tellurium (Te)
52 Metalloid
6 Polonium (Po)
84 Post-transition metal
7 Livermorium (Lv)
116 Unknown chemical properties

Legend

primordial element
naturally occurring by radioactive decay
synthetic element
Atomic number color:
red=gasblack=solid

The chalcogens (z/) are the chemical elements in group 16 of the periodic table. This group is also known as the oxygen family. It consists of the elements oxygen (O), sulfur (S), selenium (Se), tellurium (Te), and the radioactive element polonium (Po). The chemically uncharacterized synthetic element livermorium (Lv) is predicted to be a chalcogen as well.[1] Often, oxygen is treated separately from the other chalcogens, sometimes even excluded from the scope of the term "chalcogen" altogether, due to its very different chemical behavior from sulfur, selenium, tellurium, and polonium. The word "chalcogen" is derived from a combination of the Greek word khalkόs (χαλκός) principally meaning copper (the term was also used for bronze/brass, any metal in the poetic sense, ore or coin),[2] and the Latinised Greek word genēs, meaning born or produced.[3][4]

Sulfur has been known since antiquity, and oxygen was recognized as an element in the 18th century. Selenium, tellurium and polonium were discovered in the 19th century, and livermorium in 2000. All of the chalcogens have six valence electrons, leaving them two electrons short of a full outer shell. Their most common oxidation states are −2, +2, +4, and +6. They have relatively low atomic radii, especially the lighter ones.[5]

Lighter chalcogens are typically nontoxic in their elemental form, and are often critical to life, while the heavier chalcogens are typically toxic.[1] All of the naturally occurring chalcogens have some role in biological functions, either as a nutrient or a toxin. Selenium is an important nutrient but is also commonly toxic.[6] Tellurium often has unpleasant effects (although some organisms can use it), and polonium is always extremely harmful, both in its chemical toxicity and its radioactivity.

Sulfur has more than 20 allotropes, oxygen has nine, selenium has at least five, polonium has two, and only one crystal structure of tellurium has so far been discovered. There are numerous organic chalcogen compounds. Not counting oxygen, organic sulfur compounds are generally the most common, followed by organic selenium compounds and organic tellurium compounds. This trend also occurs with chalcogen pnictides and compounds containing chalcogens and carbon group elements.

Oxygen is generally obtained by separation of air into nitrogen and oxygen. Sulfur is extracted from oil and natural gas. Selenium and tellurium are produced as byproducts of copper refining. Polonium and livermorium are most available in particle accelerators. The primary use of elemental oxygen is in steelmaking. Sulfur is mostly converted into sulfuric acid, which is heavily used in the chemical industry.[6] Selenium's most common application is glassmaking. Tellurium compounds are mostly used in optical disks, electronic devices, and solar cells. Some of polonium's applications are due to its radioactivity.[1]