Group+12


 * //Zinc:// ** was discovered by Andreas Marggraf at 1746 in Germany. Origin of name: from the German word "zink"


 * __HISTORY:__ Centuries before zinc was recognized as a distinct element, zinc ores were used for making brass (a mixture of copper and zinc). A brass dating from between 1400-1000 BC has been found in Palestine. An alloy containing 87% zinc was found in prehistoric ruins in Transylvania. The smelting of zinc ores with copper was apparently discovered in Cyprus and was used later by the Romans. Metallic zinc was produced in the 13th century in India by reducing calamine (zinc carbonate, ZnCO3) with organic substances such as wool.

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 * 30 Zn ** [|Periodic table]
 * ~ Appearance ||
 * = bluish pale gray
 * ~ General properties ||
 * ~ [|Name], [|symbol], [|number] || zinc, Zn, 30 ||
 * ~ [|Element category] || [|transition metal] ||
 * ~ Category notes || Alternatively considered a [|post-transition metal] ||
 * ~ [|Group], [|period], [|block] || [|12], [|4], [|d] ||
 * ~ [|Standard atomic weight] || [|65.38][|(4)] [|g·mol−1] ||
 * ~ [|Electron configuration] || [[|Ar]] 3d10 4s2 ||
 * ~ [|Electrons] per [|shell] || 2, 8, 18, 2 ([|Image]) ||

(http://www.webelements.com/zinc/history.html) http://en.wikipedia.org/wiki/Group_%28periodic_table%29

** //Cadmium:// **
==== was discovered by Friedrich Strohmeyer at 1817 in Germany. Origin of name: somewhat confusingly, from the Latin word "cadmia" meaning "calamine" (zinc carbonate, ZnCO3) and from the Greek word "kadmeia" with the same meaning. ====
 * __HISTORY__:Cadmium was discovered by Friedrich Stromeyer in 1817 from an impurity in some samples pf zinc carbonate, ZnCO3. He noted that these particular samples changed colour on heating, which pure zinc carbonate does not. He was persistent enough to follow this observation through and he eventually isolated some cadmium metal by roasting and reduction of the sulphie.



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 * 48 Cd ** [|Periodic table]
 * ~ Appearance ||
 * = silvery gray metallic
 * ~ General properties ||
 * ~ [|Name], [|symbol], [|number] || cadmium, Cd, 48 ||
 * ~ [|Element category] || [|transition metal] ||
 * ~ Category notes || Alternatively considered a [|post-transition metal] ||
 * ~ [|Group], [|period], [|block] || [|12], [|5], [|d] ||
 * ~ [|Standard atomic weight] || [|112.411] [|g·mol−1] ||
 * ~ [|Electron configuration] || [[|Kr]] 5s2 4d10 ||
 * ~ [|Electrons] per [|shell] || 2, 8, 18, 18, 2 ([|Image]) ||

(http://www.webelements.com/cadmium/history.html) http://en.wikipedia.org/wiki/File:Cd,48.jpg

====** Mercury: ** was discovered by Known since ancient times at no data in not known. Origin of name: named after the planet "Mercury" (the origin of the symbol Hg is the Latin word "hydrargyrum" meaning "liquid silver")====

Mercury is one of the elements which has an alchemical symbol, shown below (alchemy is an ancient pursuit concerned with, for instance, the transformation of other metals into gold).
 * __HISTORY__:Mercury was known to ancient Chinese and Hindus before 2000 BC and was found in tubes in Egyptian tombs dated from 1500 BC It was used to forma amalgams of other metals around 500 BC. The Greeks used mercury in ointments and the Romans used it, unfortunately for those using it, in cosmetics.

= =

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 * 80 Hg ** [|Periodic table] |
 * ~ Appearance ||
 * = silvery
 * ~ General properties ||
 * ~ [|Name], [|symbol], [|number] || Mercury, Hg, 80 ||
 * ~ [|Element category] || [|transition metal] ||
 * ~ [|Group], [|period], [|block] || [|12], [|6], [|d] ||
 * ~ [|Standard atomic weight] || [|200.59][|(2)] [|g·mol−1] ||
 * ~ [|Electron configuration] || [[|Xe]] 4f14 5d10 6s2 ||
 * ~ [|Electrons] per [|shell] || 2, 8, 18, 32, 18, 2 ([|Image]) ||

(http://www.webelements.com/mercury/history.html) http://en.wikipedia.org/wiki/File:Pouring_liquid_mercury_bionerd.jpg