Editing Chalcogen (section)

==Production==

Approximately 100 million [[Tonne|metric tons]] of oxygen are produced yearly. Oxygen is most commonly produced by [[fractional distillation]], in which air is cooled to a liquid, then warmed, allowing all the components of air except for oxygen to turn to gases and escape. Fractionally distilling air several times can produce 99.5% pure oxygen.<ref>{{cite encyclopedia|url = https://www.britannica.com/EBchecked/topic/436806/oxygen-O/279404/Commercial-production-and-use|title = Commercial production and use|year = 2013 |access-date=November 25, 2013 |encyclopedia = [[Encyclopædia Britannica]]}}</ref> Another method with which oxygen is produced is to send a stream of dry, clean air through a bed of [[molecular sieve]]s made of [[zeolite]], which absorbs the nitrogen in the air, leaving 90 to 93% pure oxygen.<ref name = "ReferenceB"/>
[[File:AlbertaSulfurAtVancouverBC.jpg|thumb|Sulfur recovered from oil refining in Alberta, stockpiled for shipment in [[North Vancouver (city)|North Vancouver]], British Columbia]]

Sulfur can be mined in its elemental form, although this method is no longer as popular as it used to be. In 1865 a large deposit of elemental sulfur was discovered in the U.S. states of Louisiana and Texas, but it was difficult to extract at the time. In the 1890s, [[Herman Frasch]] came up with the solution of liquefying the sulfur with superheated steam and pumping the sulfur up to the surface. These days sulfur is instead more often extracted from [[oil]], [[natural gas]], and [[tar]].<ref name = "ReferenceB"/>

The world production of selenium is around 1500 metric tons per year, out of which roughly 10% is recycled. Japan is the largest producer, producing 800 metric tons of selenium per year. Other large producers include Belgium (300 metric tons per year), the United States (over 200 metric tons per year), Sweden (130 metric tons per year), and Russia (100 metric tons per year). Selenium can be extracted from the waste from the process of electrolytically refining copper. Another method of producing selenium is to farm selenium-gathering plants such as [[milk vetch]]. This method could produce three kilograms of selenium per acre, but is not commonly practiced.<ref name = "ReferenceB"/>

Tellurium is mostly produced as a by-product of the processing of copper.<ref>{{cite web |author = Callaghan, R. |url = http://minerals.usgs.gov/minerals/pubs/commodity/selenium/ |title = Selenium and Tellurium Statistics and Information |year = 2011 |access-date = November 25, 2013 |publisher = United States Geological Survey |archive-date = May 8, 2012 |archive-url = https://web.archive.org/web/20120508085217/http://minerals.usgs.gov/minerals/pubs/commodity/selenium/ |url-status = dead }}</ref> Tellurium can also be refined by [[electrolytic reduction]] of [[sodium telluride]]. The world production of tellurium is between 150 and 200 metric tons per year. The United States is one of the largest producers of tellurium, producing around 50 metric tons per year. Peru, Japan, and Canada are also large producers of tellurium.<ref name="ReferenceB"/>

Until the creation of nuclear reactors, all polonium had to be extracted from uranium ore. In modern times, most [[isotopes of polonium]] are produced by bombarding [[bismuth]] with neutrons.<ref name="The Elements"/> Polonium can also be produced by high [[neutron flux]]es in [[nuclear reactors]]. Approximately 100 grams of polonium are produced yearly.<ref name = "Factsheets"/> All the polonium produced for commercial purposes is made in the Ozersk nuclear reactor in Russia. From there, it is taken to [[Samara, Russia]] for purification, and from there to [[St. Petersburg]] for distribution. The United States is the largest consumer of polonium.<ref name = "ReferenceB"/>

All [[livermorium]] is produced artificially in [[particle accelerator]]s. The first successful production of livermorium was achieved by bombarding curium-248 atoms with [[calcium-48]] atoms. As of 2011, roughly 25 atoms of livermorium had been synthesized.<ref name = "ReferenceB"/>