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  1. GoldPrepared by Tolegen D.
  2. The name is The symbol comes from the latin ‘aurum’, from the latin meaning 'shining dawn'.
  3. Because gold is visually pleasing and workable and does not tarnish or corrode, it was one of the first metals to attract human attention. Examples of elaborate gold workmanship, many in nearly perfect condition, survive from ancient Egyptian, Minoan, Assyrian, and Etruscan artisans, and gold continues to be a highly favoured material out of which to craft jewelry and other decorative objects. (see metalwork; goldwork.)
  4. Alloys To increase its strength gold is usually alloyed with other metals, such as silver, copper, platinum or palladium, to increase its strength. The amount of gold in an alloy is measured with a unit called a karat. One karat is equal to one part in twenty-four.
  5. Gold Facts 1. Gold is the only metal that is yellow or "golden." Other metals may develop a yellowish color, but only after they have oxidized or reacted with other chemicals. 2. Nearly all the gold on Earth came from meteorites that bombarded the planet over 200 million years after it formed. 3. The element symbol for gold—Au—comes from the old Latin name for gold, aurum, which means "shining dawn" or "glow of sunrise." The word gold comes from the Germanic languages, originating from the Proto-Germanic gulþ and Proto-Indo-European ghel, meaning "yellow/green." The pure element has been known since ancient times. 4. Gold is extremely ductile. A single ounce of gold (about 28 grams) can be stretched into a gold thread 5 miles (8 kilometers) long. Gold threads can even be used in embroidery. 5. Malleability is a measure of how easily a material can be hammered into thin sheets. Gold is the most malleable element. A single ounce of gold can be beaten into a 300-square-foot sheet. A sheet of gold can be made thin enough to be transparent. Very thin sheets of gold may appear greenish blue because gold strongly reflects red and yellow. 6. Although gold is a heavy, dense metal, it is generally considered nontoxic. Gold metal flakes may be eaten in foods or drinks, although it is a common allergen for some.1 7. Pure elemental gold is 24 karats, while 18-karat gold is 75 percent pure gold, 14-karat gold is 58.5 percent pure gold, and 10-karat gold is 41.7 percent pure gold. The remaining portion of the metal usually used in gold jewelry and other items is silver, but items can also consist of other metals or a combination of metals, such as platinum, copper, palladium, zinc, nickel, iron, and cadmium. 8. Gold is a noble metal. It is relatively unreactive and resists degradation by air, moisture, or acidic conditions. While acids dissolve most metals, a special mixture of acids called aqua regia is used to dissolve gold. 9. Gold has many uses aside from its monetary and symbolic value. Among other applications, it is used in electronics, electrical wiring, dentistry, medicine, radiation shielding, and in coloring glass. 10. High-purity metallic gold is odorless and tasteless. This makes sense since the metal is unreactive. Metal ions confer flavor and odor to metallic elements and compounds.
  6. Where Gold Is Found Gold is found as the free metal and in tellurides. It is widely distributed and almost always associated with pyrite or quartz. Gold is found in veins and in alluvial deposits. Gold occurs in sea water in the amount of 0.1 to 2 mg/ton, depending on the location of the sample. Transmuting lead into gold was one of the major gold of the alchemists. Modern nuclear chemists have found methods to accomplish this historic task.
  7. money Because of its unique qualities, gold has been the one material that is universally accepted in exchange for goods and services. In the form of coins or bullion, gold has occasionally played a major role as a high- denomination currency, although silver was generally the standard medium of payments in the world’s trading systems. Gold began to serve as backing for paper-currency systems when they became widespread in the 19th century, and from the 1870s until World War I the gold standard was the basis for the world’s currencies. Although gold’s official role in the international monetary system had come to an end by the 1970s, the metal remains a highly regarded reserve asset, and approximately 45 percent of all the world’s gold is held by governments and central banks for this purpose. Gold is still accepted by all nations as a medium of international payment.
  8. From were On Earth, gold finally reached us some 200 million years after the formation of the planet when meteorites packed with gold and other metals bombarded its surface. During the formation of Earth, molten iron sank to its centre to make the core. This took with it the vast majority of the planet’s precious metals — such as gold and platinum. In fact, there are enough precious metals in the core to cover the entire surface of Earth with a four-metre thick layer.
  9. history Gold has been known since prehistoric times and was one of the first metals to be worked, mainly because it was to be found as nuggets or as particles in the beds of streams. Such was the demand that by 2000 BC the Egyptians began mining gold. The death mask of Tutankhamen, who died in 1323 BC, contained 100 kg of the metal. The royal graves of ancient Ur (modern Iraq), which flourished from 3800 to 2000 BC, also contained gold objects. The minting of gold coins began around 640 BC in the Kingdom of Lydia (situated in what is now modern Turkey) using electrum, a native alloy of gold and silver. The first pure gold coins were minted in the reign of King Croesus, who ruled from 561–547 BC.
  10. abundance An attractive and highly valued metal, gold has been known for at least 5500 years. Gold is sometimes found free in nature but it is usually found in conjunction with silver, quartz (SiO2), calcite (CaCO3), lead, tellurium, zinc or copper. There is roughly 1 milligram of gold dissolved in every ton of seawater, although extracting it currently costs more than the gold is worth. 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. Veins enriched in gold form when the gold was carried up from great depths with other minerals, in an aqueous solution, and later precipitated. The gold in rocks usually occurs as invisible disseminated grains, more rarely as flakes large enough to be seen, and even more rarely as masses or veinlets. Crystals about 2.5 cm (1 inch) or more across have been found in California. Masses, some on the order of 90 kg (200 pounds), have been reported from Australia. Natural abundance Gold is one of the few elements to occur in a natural state. It is found in veins and alluvial deposits. About 1500 tonnes of gold are mined each year. About two-thirds of this comes from South Africa and most of the rest from Russia. Seawater contains about 4 grams of gold in 1,000,000 tonnes of water. Overall this is a huge amount of gold stored in the oceans but, because the concentration is so low, attempts to reclaim this gold have always failed.
  11. Gold is, in fact, one of the first metals known to man with its origin being dated back to 3400 BCE by the Egyptians. Gold has always been a symbol of wealth and beauty. During Egypt's reign of Pharaoh's, the Egyptians would often amass tremendous amounts of gold just to cover the coffin of a deceased Pharaoh. Interestingly enough, when King Tutankhamun, commonly referred to as King Tut, died, his coffin contained approximately 112 kg of gold. For those of you unfamiliar with the metric system, 112 kg is about 247 lbs. To give a direct comparison, that is more gold per pound than the size of an average NFL running back! Moreover, the discovery of gold was the cause of a great migration of people to California during the late 1800s during the California Gold Rush.
  12. Gold (Au), chemical element metal of Group 11 (Ib), Period 6, of the periodic table. Along with silver and copper were the first three elements known to man. They were all used as primitive money well before the first gold coins which appeared in Egypt around 3400 BC. Gold has always been a symbol of wealth and beauty.

Hinweis der Redaktion

  1. Gold is shiny. Gold is glamorous. Gold is the subject of my presentation. Gold, in sum, is considered one of the most precious metals in all the world.
  2. Gold (Au), chemical element metal of Group 11 (Ib), Period 6, of the periodic table. Along with silver and copper were the first three elements known to man. They were all used as primitive money well before the first gold coins which appeared in Egypt around 3400 BC. Gold has always been a symbol of wealth and beauty.
  3. Estimated Crustal Abundance: 4×10-3 mg/kg Estimated Oceanic Abundance: 4×10-6 mg/litr Just over Gold is the seventh most dense metal. This is one of the most efficient ways that spheres can pack together, using 74 % of the space.
  4. Thin sheets of gold, known as gold leaf, are primarily used in arts and crafts for gilding.
  5. Thin gold wires are used inside computer chips to produce circuits.  for plating contacts, terminals, printed circuits, and semiconductor systems This is used in gears for watches, artificial limb joints, cheap jewellery and electrical connectors. It is ideal for protecting electrical copper components because it conducts electricity well and does not corrode (which would break the contact). , so it can be used to make electrical connectors and printed circuit boards. and can be used to help shield spacecraft and skyscrapers from the sun's heat. Gold coated mirrors can be used to make telescopes that are sensitive to infrared light.