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Concept
Groupe 11 du tableau périodique
Résumé
Group 11, by modern IUPAC numbering, is a group of chemical elements in the periodic table, consisting of copper (Cu), silver (Ag), and gold (Au), and roentgenium (Rg), although no chemical experiments have yet been carried out to confirm that roentgenium behaves like the heavier homologue to gold. Group 11 is also known as the coinage metals, due to their usage in minting coins—while the rise in metal prices mean that silver and gold are no longer used for circulating currency, remaining in use for bullion, copper remains a common metal in coins to date, either in the form of copper clad coinage or as part of the cupronickel alloy. They were most likely the first three elements discovered. Copper, silver, and gold all occur naturally in elemental form.
All the elements of the group except roentgenium have been known since prehistoric times, as all of them occur in metallic form in nature and no extraction metallurgy is necessary to produce them.
Copper was known and used around 4000 BC and many items, weapons and materials were made and used with copper.
The first evidence of silver mining dates back to 3000 B.C., in Turkey and Greece, according to the RSC. Ancient people even figured out how to refine silver.
The earliest recorded metal employed by humans appears to be gold, which can be found free or "native". Small amounts of natural gold have been found in Spanish caves used during the late Paleolithic period, c. 40,000 BC. Gold artifacts made their first appearance at the very beginning of the pre-dynastic period in Egypt, at the end of the fifth millennium BC and the start of the fourth, and smelting was developed during the course of the 4th millennium; gold artifacts appear in the archeology of Lower Mesopotamia during the early 4th millennium.
Roentgenium was made in 1994 by bombarding nickel-64 atoms into bismuth-209 to make roentgenium-272.
Like other groups, the members of this family show patterns in electron configuration, especially in the outermost shells, resulting in trends in chemical behavior, although roentgenium is probably an exception:
All group 11 elements are relatively inert, corrosion-resistant metals.
Source officielle
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