What is Magnesium?
{{redirects|Mg|other uses|MG}} {{Infobox magnesium}} [[File:Magnesium.jpg|thumb|Magnesium]] '''Magnesium''' ( /mæɡˈniːziəm/ mag-NEE-zee-əm) is a [[chemical element]]. It has the symbol ''Mg'', [[atomic number]] 12 and common [[oxidation state]] +2. It is an [[alkaline earth metal]] and the eighth most [[Abundance of chemical elements|abundant]] [[Chemical element|element]] in the [[Earth's crust]]. It makes up 2% of the [[mass]] of the crust. It is the ninth most common element in the [[Observable universe|known]] [[universe]].<ref>{{cite book|last = Ash|first = Russell|title = The Top 10 of Everything 2006: The Ultimate Book of Lists|publisher = Dk Pub|year = 2005|url = http://plymouthlibrary.org/faqelements.htm|isbn = 0756613213|access-date = 2011-09-26|archive-date = 2010-02-10|archive-url = https://web.archive.org/web/20100210170504/http://plymouthlibrary.org/faqelements.htm|url-status = dead}}.</ref> This is because it is easily built up in [[supernova]] stars by addition of three [[helium]] [[nucleus (physics)|nuclei]] to [[carbon]] (which in turn is made from three helium nuclei). Magnesium [[ion]]'s high [[solubility]] in water helps ensure that it is the third most abundant element dissolved in [[seawater]].<ref>{{cite news|url=http://www.seafriends.org.nz/oceano/seawater.htm#composition|title=The chemical composition of seawater|author=Anthoni, J Floor|year=2006}}</ref> Magnesium is the 11th most abundant element by mass in the [[human body]]. Its ions are essential to all living [[Cell|cells]]. The ions play a major role in manipulating important biological [[polyphosphate]] compounds like [[Adenosine triphosphate|ATP]], [[DNA]], and [[RNA]]. Hundreds of [[enzyme]]s thus require magnesium ions to function. Magnesium is also the metallic ion at the center of [[chlorophyll]]. It is a common [[additive]] to [[fertilizer]]s.<ref>{{cite web|url=http://www.mg12.info|title=Magnesium in health}}</ref> Magnesium ions are [[sour]] to the taste, and in low concentrations help to impart a natural tartness to fre