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Check out these fun 24-karat nuggets about gold. The post 13 Facts You Probably Never Knew About Gold appeared first on Reader's Digest.
Gold, a chemical element; Genomes OnLine Database; Global-scale Observations of the Limb and Disk, a NASA Explorer Mission of Opportunity; GOLD (parser), an open-source parser-generator of BNF-based grammars; Graduates of the Last Decade, an Institute of Electrical and Electronics Engineers program to garner more university level student members
Gold is currently considered the heaviest monoisotopic element. Bismuth formerly held that distinction until alpha-decay of the 209 Bi isotope was observed. All isotopes of gold are either radioactive or, in the case of 197 Au, observationally stable, meaning that 197 Au is predicted to be radioactive but no actual decay has been observed. [4]
The elements to the left of gold and silver have incompletely filled d-bands, which is believed to play a role in their catalytic properties. A common explanation is the d-band filling model of Hammer and Jens Nørskov , [ 18 ] [ 19 ] where the total d-bands are considered, not just the unoccupied states.
Gold is a soft metal (MH 2.5–3) [41] that is easily deformed. [42] It has a close-packed face-centred cubic structure (BCN 12). [34] The chemistry of gold is dominated by its +3 valence state; all such compounds of gold feature covalent bonding, [43] as do its stable +1 compounds. [44]
A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z). [ 1 ] The definitive visualisation of all 118 elements is the periodic table of the elements , whose history along the principles of the periodic law was one of the founding ...
Most gold is mined as native metal and can be found as nuggets, veins or wires of gold in a rock matrix, or fine grains of gold, mixed in with sediments or bound within rock. The iconic image of gold mining for many is gold panning , which is a method of separating flakes and nuggets of pure gold from river sediments due to their great density .
It was recognised as an element by Guyton de Morveau, Lavoisier, Berthollet, and Fourcroy in 1787. [6] The earliest gold artifacts were discovered at the site of Wadi Qana in the Levant. [13] Silver is estimated to have been discovered in Asia Minor shortly after copper and gold. [14] There is evidence that iron was known from before 5000 BC. [15]