Gold Kryzhanovskaya Dana Group 113
Gold is a dense, soft, shiny, malleable and ductile metal. It is a chemical element with the symbol Au (aurum in Latin, meaning glow of sunrise) and atomic number 79. It has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water.
Gold resists attacks by individual acids, but it can be dissolved by the aqua regia (nitro-hydrochloric acid), so named because it dissolves gold. Gold also dissolves in alkaline solutions of cyanide, which have been used in mining.
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. Gold standards have sometimes been a monetary policies, but were widely supplanted by fiat currency starting in the 1930 s. The last gold certificate and gold coin currencies were issued in the U. S. in 1932. In Europe, most countries left the gold standard with the start of World War I in 1914 and, with huge war debts, failed to return to gold as a medium of exchange.
A total of 171, 300 tonnes of gold have been mined in human history, according to GFMS as of 2011. This is roughly equivalent to 5. 5 billion troy ounces or, in terms of volume, about 8876 m 3, or a cube 20. 7 m on a side. The world consumption of new gold produced is about 50% in jewelry, 40% in investments, and 10% in industry.
Gold readily creates alloys with many other metals. In addition, gold is very dense, a cubic meter weighing 19, 300 kg. By comparison, the density of lead is 11, 340 kg/m 3, and that of the densest element, osmium, is 22, 610 kg/m 3.
Common colored gold alloys such as rose gold can be created by the addition of various amounts of copper and silver. Alloys containing palladium or nickel are also important in commercial jewelry as these produce white gold alloys. Less commonly, addition of manganese, aluminium, iron, indium and other elements can produce more unusual colors of gold for various applications. Lemon gold White gold Rose gold Blue gold
Production World production in for 2011 was at 2, 700 tonnes, compared to 2, 260 tonnes for 2008. Since the 1880 s, South Africa has been the source for a large proportion of the world's gold supply, with about 50% of all gold ever produced having come from South Africa. Production in 1970 accounted for 79% of the world supply, producing about 1, 480 tonnes. In 2007 China (with 276 tonnes) overtook South Africa as the world's largest gold producer, the first time since 1905 that South Africa has not been the largest. Other major producers are the United States, Australia, Russia and Peru.
As for Ukraine The gold mining subindustry of Ukraine - developed in the last years of the twentieth century. , Under Soviet rule was absent. The most explored for 1999 is gold-ore district, located in the Carpathian volcanic belt. Promising fields of the Ukrainian Carpathians is Muzhievske, Berehivske, Saulyak, stocks of which are millions of tons of ore, and the average gold content of 8. 6 g / t. Also Middle Dnieper
Consequently, Ukraine has a real geological conditions and adequate research, design, exploration, mining, technology, engineering capabilities and infrastructure to create a national gold mining and gold industries. To improve and consolidate existing potentials (complete geological exploration, development and industrial testing flowsheets enrichment and processing of goldbearing ore concentrates, building mines, concentrators and tailings, reconstruction hydrometallurgical plants) should be estimated to 5 years and invest 700 - 800 million.
Jewelry Because of the softness of pure gold, it is usually alloyed with base metals for use in jewelry, altering its hardness and ductility, melting point, color and other properties. Alloys with lower caratage, typically, contain higher percentages of copper, or other base metals or silver or palladium in the alloy. Copper is the most commonly used base metal, yielding a redder color.
Medicine In medieval times, gold was often seen as beneficial for the health, in the belief that something so rare and beautiful could not be anything but healthy. Even some modern esotericists and forms of alternative medicine assign metallic gold a healing power.
Gold alloys are used in restorative dentistry, especially in tooth restorations, such as crowns and permanent bridges. Nuclear medicine : The isotope gold-198 (half-life 2. 7 days) is used, in nuclear medicine, in some cancer treatments and for treating other diseases. Cosmetics.
Food and drink Gold can be used in food and has the E number 175. Gold leaf, flake or dust is used on and in some gourmet foods, notably sweets and drinks as decorative ingredient or in the belief that something that valuable and rare must be beneficial for one's health.
Industry Gold can be made into thread and used in embroidery.
As gold is a good reflector of electromagnetic radiation such as infrared and visible light as well as radio waves, it is used for the protective coatings on many artificial satellites, in thermal protection suits and astronauts' helmets. Gold is used as the reflective layer on some high-end CDs. Automobiles may use gold for heat shielding. Gold can be manufactured so thin that it appears transparent. It is used in some aircraft cockpit windows for de-icing or anti-icing by passing electricity through it. The heat produced by the resistance of the gold is enough to deter ice from forming.
Gold is highly conductive to electricity it is also used in electrical contacts because of its resistance to corrosion, and lack of toxicity.
As for the history Gold artifacts were used for burial in Ancient Egypt.
Conclusion Gold – is precious metal. It is a dense, soft, shiny, malleable and ductile metal. It is a chemical element with the symbol Au and atomic number 79. Multifunctional and widespread – it`s plus; Gold rush and prize – it`s minus.
References Magnetic susceptibility of the elements and inorganic compounds in Lide, D. R. , ed. (2005). CRC Handbook of Chemistry and Physics (86 th ed. ). Boca Raton (FL): CRC Press. ISBN 0 -8493 -0486 -5. Soos, Andy (2011 -01 -06). "Gold Mining Boom Increasing Mercury Pollution Risk". Advanced Media Solutions, Inc. (Oilprice. com). Retrieved 2011 -03 -26. http: //www. bbc. co. uk/news/science-environment-14827624 http: //www. sciencedaily. com/releases/2011/09/110907132044. htm http: //www. ees. rochester. edu/ees 119/reading 2. pdf http: //www. huffingtonpost. com/2011/09/10/ meteor-shower-gold_n_955448. html http: //www. nature. com/nature/journal/v 477/n 7363/ full/nature 10399. html#/access http: //superiormining. com/properties/south_africa/ mangalisa/geology/