atomic number 79
This metal has been a valuable and highly sought-after precious metal for coinage, jewelry, and other arts since long before the beginning of recorded history. In the past, a gold standard was often implemented as a monetary policy within and between nations, but gold coins ceased to be minted as a circulating currency in the 1930s, and the world gold standard (see article for details) was finally abandoned for a fiat currency system after 1976. The historical value of gold was rooted in its medium rarity, easy handling and minting, easy smelting, non-corrosiveness, distinct color, and non-reactivity to other elements.
Gold’s high malleability, ductility, resistance to corrosion and most other chemical reactions, and conductivity of electricity have led to its continued use in corrosion resistant electrical connectors in all types of computerized devices (its chief industrial use). Gold is also used in infrared shielding, colored-glass production, and gold leafing. Certain gold salts are still used as anti-inflammatories in medicine.
The symbol Au is from the Latin: aurum, the Latin word for "gold". The Proto-Indo-Europeanancestor of aurum was *h₂é-h₂us-o-, meaning "glow". This word is derived from the same root(Proto-Indo-European *h₂u̯es- "to dawn") as *h₂éu̯sōs, the ancestor of the Latin word Aurora, "dawn". This etymological relationship is presumably behind the frequent claim in scientific publications that aurum meant "shining dawn".
One main goal of the alchemists was to produce gold from other substances, such as lead — presumably by the interaction with a mythical substance called the philosopher's stone. Although they never succeeded in this attempt, the alchemists promoted an interest in what can be done with substances, and this laid a foundation for today's chemistry. Their symbol for gold was the circle with a point at its center (☉), which was also the astrological symbol and the ancient Chinese character for the Sun.
$1,307/oz so far in 2015
Gold's atomic number of 79 makes it one of the higher atomic number elements that occur naturally. Although traditionally, gold is thought to have formed by supernova nucleosynthesis., a new theory suggests that gold and other elements heavier than iron are made by the collision of neutron stars instead.Either way, satellite spectrometers in theory detect the resulting gold, "but we have no spectroscopic evidence that [such] elements have truly been produced."
These gold nucleogenesis theories hold that the resulting explosions scattered metal-containing dusts (including heavy elements like gold) into the region of space in which they later condensed into our solar system and the Earth. Because the Earth was molten when it was just formed, almost all of the gold present on Earth sank into the core. Most of the gold that is present today in the Earth's crust and mantle is thought to have been delivered to Earth later, by asteroid impacts during the late heavy