Group 11 element Group 11 element 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). Roentgenium (Rg) is also placed in this group in the periodic table, although no chemical experiments have yet been carried out to confirm that it behaves like the heavier homologue to gold. Group 11 is also known as the "coinage metals", due to their former usage. 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
Period 5 element various oxidation states in minerals. Industrially, molybdenum compounds are used in high-pressure and high-temperature applications, as pigments and catalysts. Molybdenum minerals have long been known, but the element was "discovered" (in the sense of differentiating it as a new entity from the mineral salts of other metals) in 1778 by Carl Wilhelm Scheele. The metal was first isolated in 1781 by Peter Jacob Hjelm. Most molybdenum compounds have low solubility in water, but the molybdate ion MoO is soluble and forms when molybdenum-containing minerals are in contact with oxygen and water. Technetium is the chemical element with atomic number 43