Certain gold salts are still used as anti-inflammatories in medicine. Gold is also used in infrared shielding, the production of colored glass, gold leafing, and tooth restoration. 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). The world's consumption of new gold produced is about 50% in jewelry, 40% in investments, and 10% in industry. This is equal to a cube with each side measuring roughly 21.7 meters (71 ft). A total of around 201,296 tonnes of gold exists above ground, as of 2020. In 2020, the world's largest gold producer was China, followed by Russia and Australia. Gold coins ceased to be minted as a circulating currency in the 1930s, and the world gold standard was abandoned for a fiat currency system after the Nixon shock measures of 1971. Element symbols for chemical elements normally consist of one or two letters from the Latin alphabet and are written with the first letter capitalised. The unit carat is used for the percent purity of gold, especially in jewellery. ![]() About 1 ounce of gold can be hammered or pressed into 300 square feet sheet. In the past, a gold standard was often implemented as a monetary policy. Chemical symbols are the abbreviations used in chemistry for chemical elements, functional groups and chemical compounds. Gold is a soft metal and is usually used in alloyed form to provide strength and durability. Gold also dissolves in mercury, forming amalgam alloys, and as the gold acts simply as a solute, this is not a chemical reaction.Ī relatively rare element, gold is a precious metal that has been used for coinage, jewelry, and other arts throughout recorded history. Gold dissolves in alkaline solutions of cyanide, which are used in mining and electroplating. Gold is insoluble in nitric acid alone, 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 is resistant to most acids, though it does dissolve in aqua regia (a mixture of nitric acid and hydrochloric acid), forming a soluble tetrachloroaurate anion. Less commonly, it occurs in minerals as gold compounds, often with tellurium ( gold tellurides). It occurs in a solid solution series with the native element silver (as in electrum), naturally alloyed with other metals like copper and palladium, and mineral inclusions such as within pyrite. Chlorauric acid (HAuCl 4) is used to preserve photographs by replacing the silver atoms present in an image.Gold often occurs in free elemental ( native state), as nuggets or grains, in rocks, veins, and alluvial deposits. Gold sodium thiosulfate (AuNa 3O 6S 4) is used as a treatment for arthritis. Gold coated mirrors can be used to make telescopes that are sensitive to infrared light.Ī radioactive isotope of gold, gold-198, is used for treating cancer. Gold is also a good reflector of infrared radiation and can be used to help shield spacecraft and skyscrapers from the sun's heat. Gold is a good conductor of heat and electricity and does not tarnish when it is exposed to the air, so it can be used to make electrical connectors and printed circuit boards. One karat is equal to one part in twenty-four, so an 18 karat gold ring contains 18 parts pure gold and 6 parts alloy material. The amount of gold in an alloy is measured with a unit called a karat. Gold alloys are used to make jewelry, decorative items, dental fillings and coins. Pure gold is soft and is usually alloyed with other metals, such as silver, copper, platinum or palladium, to increase its strength. ![]() One sheet of gold leaf can be as thin as 0.000127 millimeters, or about 400 times thinner than a human hair. Thin sheets of gold, known as gold leaf, are primarily used in arts and crafts for gilding. ![]() A single ounce of gold can be beaten into a sheet measuring roughly 5 meters on a side. Gold is the most malleable and ductile of all known metals. It has been estimated that all of the gold that has currently been refined could be placed in a cube measuring 20 meters on a side. There is roughly 1 milligram of gold dissolved in every ton of seawater, although extracting it currently costs more than the gold is worth. Gold is sometimes found free in nature but it is usually found in conjunction with silver, quartz (SiO 2), calcite (CaCO 3), lead, tellurium, zinc or copper. An attractive and highly valued metal, gold has been known for at least 5500 years.
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