Editing Period 6 element (section)

===Mercury===
{{main|Mercury (element)}}
'''Mercury''' is a [[chemical element]] with the symbol '''Hg''' and [[atomic number]] 80. It is also known as '''quicksilver'''<!--ref>{{cite web|url=http://dictionary.reference.com/browse/quicksilver|title=quicksilver definition |access-date=13 October 2008|publisher=Dictionary.com Unabridged (v 1.1)}}</ref---> or '''hydrargyrum''' ( < Greek "[[Wiktionary:en:hydr-|hydr-]]" ''water'' and "[[Wiktionary:en:άργυρος|argyros]]" ''silver''). A heavy, silvery [[d-block]] element, mercury is the only metal that is liquid at [[standard conditions for temperature and pressure]]; the only other element that is liquid under these conditions is [[bromine]], though metals such as [[caesium]], [[francium]], [[gallium]], and [[rubidium]] melt just above room temperature. With a [[freezing point]] of −38.83&nbsp;°C and [[boiling point]] of 356.73&nbsp;°C, mercury has one of the narrowest ranges of its liquid state of any metal.<ref>{{cite web|url=http://antoine.frostburg.edu/chem/senese/101/inorganic/faq/why-is-mercury-liquid.shtml| title=Why is mercury a liquid at STP?| access-date=May 1, 2007| publisher=General Chemistry Online at Frostburg State University| author=Senese, F}}</ref><ref name="Norrby">{{cite journal|author=Norrby, L.J.|title=Why is mercury liquid? Or, why do relativistic effects not get into chemistry textbooks?| journal= Journal of Chemical Education|volume=68|issue=2|page=110 |year=1991|doi=10.1021/ed068p110|bibcode=1991JChEd..68..110N}}</ref><ref>{{RubberBible86th|pages=4.125–4.126}}</ref>

Mercury occurs in deposits throughout the world mostly as [[cinnabar]] ([[mercuric sulfide]]). The red pigment [[vermilion]] is mostly obtained by reduction from cinnabar. Cinnabar is highly toxic by ingestion or inhalation of the dust. [[Mercury poisoning]] can also result from exposure to water-soluble forms of mercury (such as [[mercuric chloride]] or [[methylmercury]]), inhalation of mercury vapor, or eating seafood contaminated with mercury.

Mercury is used in [[thermometer]]s, [[barometer]]s, [[manometer]]s, [[sphygmomanometer]]s, [[float valve]]s, [[mercury switch]]es, and other devices though concerns about the element's toxicity have led to mercury thermometers and sphygmomanometers being largely phased out in clinical environments in favor of [[ethanol|alcohol]]-filled, [[galinstan]]-filled, digital, or [[thermistor]]-based instruments. It remains in use in scientific research applications and in [[amalgam (dentistry)|amalgam]] material for [[dental restoration]]. It is used in lighting: electricity passed through mercury vapor in a phosphor tube produces short-wave [[ultraviolet light]] which then causes the phosphor to [[fluoresce]], making visible light.