Chalcogen
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2008-07-08T20:03:27Z
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{| style="float: right; border: 1px solid #ccc; margin: 0.5em 0pt 0.8em 1.4em; padding: 3px !important; width: 75px;"
! [[Group (periodic table)|Group]] →!! 16
|-
! ↓ [[Period (periodic table)|Period]]
|-
! [[Period 2 element|2]]
| {{element cell| 8|Oxygen|O| |Gas|Nonmetals|Primordial}}
|-
! [[Period 3 element|3]]
| {{element cell|16|Sulfur|S| |Solid|Nonmetals|Primordial}}
|-
! [[Period 4 element|4]]
| {{element cell|34|Selenium|Se| |Solid|Nonmetals|Primordial}}
|-
! [[Period 5 element|5]]
| {{element cell|52|Tellurium|Te| |Solid|Metalloids|Primordial}}
|-
! [[Period 6 element|6]]
| {{element cell|84|Polonium|Po| |Solid|Metalloids|Natural radio}}
|-
! [[Period 7 element|7]]
| {{element cell|116|Ununhexium|Uuh| |Solid|Poor metals|Synthetic}}
|}
The '''chalcogens''' are the name for the [[periodic table group]] 16 (old-style: VIB or VIA) in the [[periodic table]]. It is sometimes known as the '''oxygen family'''. It consists of the [[chemical element|elements]] [[oxygen]] ('''O'''), [[sulfur]] ('''S'''), [[selenium]] ('''Se'''), [[tellurium]] ('''Te'''), the radioactive [[polonium]] ('''Po'''), and the synthetic [[ununhexium]] ('''Uuh'''). The compounds of the heavier chalcogens (particularly the [[sulfide]]s, [[selenide]]s, and [[telluride (chemistry)|telluride]]s) are collectively known as '''chalcogenides'''. Unless grouped with a heavier chalcogen, [[oxide]]s are not considered chalcogenides.<ref>{{Ref patent|country=US |number=2007092648 |status= application |title=Chalcogenide solar cells |pubdate=2007-04-26 |fdate=2005-11-29 |invent1= Jeroen K. J. Van Duren |assign1= Nanosolar, Inc.}}</ref>
The name is generally considered to mean "ore former" from the [[Greek language|Greek]] ''chalcos'' "''ore''" and ''-gen'' "formation". <ref>[http://jchemed.chem.wisc.edu/Journal/Issues/2001/Oct/abs1333_1.html A Second Note on the Term "Chalcogen"]</ref>
Oxygen and sulfur are [[nonmetal]]s, and polonium, selenium and tellurium are [[metalloid]] [[semiconductor]]s (i.e., their electrical properties are between those of a metal and an [[electrical insulation|insulator]]). Nevertheless, tellurium, as well as selenium, is often referred to as a metal when in elemental form.
Chalcogens are quite common as minerals. For example, [[pyrite]] (FeS<sub>2</sub>) is an [[iron ore]] and AuTe<sub>2</sub> gave its name to the gold rush town of [[Telluride, Colorado]], in the [[United States]].
The formal [[oxidation number]] of the chalcogens is generally −2 in a chalcogenide but other values, such as −1 in [[pyrite]], can be attained.
The highest formal oxidation number +6 is found in [[sulfate]]s, [[selenate]]s and [[tellurate]]s, such as in sodium selenate (Na<sub>2</sub>SeO<sub>4</sub>). Modern chemical understanding based on [[quantum chemistry|quantum theory]] supersedes the use of formal oxidation numbers in favour of a [[Hartree-Fock|many-electron wavefunction]] approach allowing detailed computer simulation. The former concept, while flawed, is still useful in thought experiments.{{Fact|date=April 2008}}
{|style="text-align: center;" border="0" cellpadding="2"
|+ '''Explanation of above periodic table slice:'''
! bgcolor="{{element color/Nonmetals}}" | [[Nonmetal]]s
! bgcolor="{{element color/Metalloids}}" | [[Metalloid]]s
! bgcolor="{{element color/Poor metals}}" | [[Poor metal]]s
| Atomic numbers in <font color="{{element color/Gas}}">{{element color/Gas}}</font> are gases
| Atomic numbers in <font color="{{element color/Solid}}">{{element color/Solid}}</font> are solids
| style="border:{{element frame/Primordial}};" | Solid borders indicate [[primordial element]]s (older than the [[Earth]])
| style="border:{{element frame/Natural radio}};" | Dashed borders indicate [[radioactive decay|radioactive]] natural elements
| style="border:{{element frame/Synthetic}};" | Dotted borders indicate radioactive [[synthetic element]]s
|}
{{PeriodicTablesFooter}}
== See also ==
* [[Gold chalcogenides]]
* [[Periodic table]]
== External links ==
{{reflist}}
[[Category:Periodic table]]
[[Category:Chalcogens|*]]
{{Link FA|lmo}}
[[ar:مجموعة كالكوجين]]
[[ast:Elementos del grupu 16]]
[[bs:Halkogeni elementi]]
[[bg:Халкоген]]
[[ca:Calcogen]]
[[cs:Chalkogen]]
[[de:Chalkogene]]
[[es:Anfígeno]]
[[eo:Elemento de grupo 16]]
[[eu:Anfigeno]]
[[fr:Chalcogène]]
[[ko:16족 원소]]
[[it:Elementi del gruppo 16]]
[[sw:Kundi la Halkojeni]]
[[la:Chalcogenica]]
[[lmo:Calcògen]]
[[nl:Zuurstofgroep]]
[[ja:第16族元素]]
[[nn:Chalkogen]]
[[nds:Chalkogen]]
[[pl:Tlenowce]]
[[pt:Calcogênio]]
[[ru:Халькогены]]
[[qu:Ch'uqichaq]]
[[sk:Chalkogény]]
[[sl:Halkogen]]
[[sr:16. група хемијских елемената]]
[[sh:16. grupa hemijskih elemenata]]
[[fi:Happiryhmä]]
[[sv:Syregruppen]]
[[th:แชลโคเจน]]
[[vi:Nhóm nguyên tố 16]]
[[tr:Kalkojen]]
[[zh:氧族元素]]