Gold Wikipedia audio article

This is an audio version of the Wikipedia Article: Gold Listening is a more natural way of learning when compared to reading. Written language only began at around 3200 BC but spoken language has existed long ago. Learning by listening is a great way to: - increases imagination and understanding - improves your listening skills - improves your own spoken accent - learn while on the move - reduce eye strain Now learn the vast amount of general knowledge available on Wikipedia through audio audio article. You could even learn subconsciously by playing the audio while you are sleeping! If you are planning to listen a lot you could try using a bone conduction headphone or a standard speaker instead of an earphone. You can find other Wikipedia audio articles too at: In case you dont find one that you were looking for put a comment. This video uses Google TTS en-US-Standard-D voice. SUMMARY Gold is a chemical element with symbol Au from Latin: aurum and atomic number 79 making it one of the higher atomic number elements that occur naturally. In its purest form it is a bright slightly reddish yellow dense soft malleable and ductile metal. Chemically gold is a transition metal and a group 11 element. It is 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 in veins and in alluvial deposits. It occurs in a solid solution series with the native element silver as electrum and also naturally alloyed with copper and palladium. Less commonly it occurs in minerals as gold compounds often with tellurium gold tellurides. Gold is resistant to most acids though it does dissolve in aqua regia a mixture of nitric acid and hydrochloric acid which forms a soluble tetrachloroaurate anion. Gold is insoluble in nitric acid which dissolves silver and base metals a property that has long been used to refine gold and to confirm the presence of gold in metallic objects 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 but 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 but 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 1971. A total of 186700 tonnes of gold exists above ground as of 2015. The world consumption of new gold produced is about 50 in jewelry 40 in investments and 10 in industry. Golds 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 gold leafing and tooth restoration. Certain gold salts are still used as anti-inflammatories in medicine. As of 2016 the worlds largest gold producer by far was China with 450 tonnes per year.,

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