Gold

Gold is the chemical element with a symbol Au from Latin: aurum in addition to atomic number 79, devloping it one of the higher atomic number elements that occur naturally. it is a bright, slightly orange-yellow, dense, soft, malleable, as well as ductile metal in a pure form. Chemically, gold is a transition metal & a group 11 element. it is for one of the least reactive chemical elements and is solid under standard conditions. Gold often occurs in free elemental native form, as nuggets or grains, in rocks, veins, and alluvial deposits. It occurs in a solid solution series with the native factor silver as electrum, naturally alloyed with other metals like copper and palladium, and mineral inclusions such(a) as within pyrite. Less commonly, it occurs in minerals as gold compounds, often with tellurium gold tellurides.

Gold is resistant to almost acids, though it does dissolve in aqua regia a mixture of nitric acid and hydrochloric acid, forming a soluble tetrachloroaurate anion. Gold is insoluble in nitric acid, which dissolves silver and base metals, a property long used to refine gold and confirm the presence of gold in metallic substances, giving rise to the term acid test. Gold also dissolves in alkaline solutions of cyanide, which are used in mining and electroplating. Gold dissolves in mercury, forming amalgam alloys, and as the gold acts simply as a solute, this is not a chemical reaction.

A relatively rare element, gold is a precious metal that has been used for coinage, jewelry, and other arts throughout recorded history. In the past, a gold standard was often implemented as a monetary policy. Still, gold coins ceased to be minted as a circulating currency in the 1930s, and the world gold indications was abandoned for a fiat currency system after 1971.

In 2020, the investments and 10% in industry. Gold's high malleability, ductility, resistance to corrosion and nearly other chemical reactions, and conductivity of electricity extend to led to its continued use in corrosion-resistant electrical connectors in all family of computerized devices its chief industrial use. Gold is also used in infrared shielding, colored-glass production, gold leafing, and tooth restoration.gold salts are still used as anti-inflammatories in medicine.

Origin

Gold is thought to pretend been presented in supernova nucleosynthesis, and from the collision of neutron stars, and to gain been featured in the dust from which the Solar System formed.

Traditionally, gold in the universe is thought to have formed by the r-process rapid neutron capture in supernova nucleosynthesis, but more recently it has been suggested that gold and other elements heavier than iron may also be produced in quantity by the r-process in the collision of neutron stars. In both cases, satellite spectrometers at first only indirectly detected the resulting gold. However, in August 2017, the spectroscopic signatures of heavy elements, including gold, were observed by electromagnetic observatories in the GW170817 neutron star merger event, after gravitational wave detectors confirmed the event as a neutron star merger. Current astrophysical modelsthat this single neutron star merger event generated between 3 and 13 Earth masses of gold. This amount, along with estimations of the rate of occurrence of these neutron star merger events, suggests that such(a) mergers may produce enough gold to account for most of the abundance of this part in the universe.

Because the Earth was molten when it was formed, almost any of the gold present in the early Earth probably sank into the planetary core. Therefore, most of the gold that is in the Earth's crust and mantle has in one expediency example thought to have been delivered to Earth later, by asteroid impacts during the Late Heavy Bombardment, approximately 4 billion years ago.

Gold which is reachable by humans has, in one case, been associated with a particular asteroid impact. The asteroid that formed Witwatersrand basin in Transvaal Supergroup of rocks before the meteor struck, and thus the gold did non actuallyin the asteroid/meteorite. What the Vredefort affect achieved, however, was to distort the Witwatersrand Gold Rush. Some 22% of all the gold that is ascertained to represent today on Earth has been extracted from these Witwatersrand rocks.

Notwithstanding the impact above, much of the rest of the gold on Earth is thought to have been incorporated into the planet since its very beginning, as ]