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Gold, nothing can compare to this precious metal. A symbol of wealth and prosperity, it has been a value for explorers and adventurers and a lure for conquerors. Today it is vital to commerce and finance; popular in ornamentation, and increasing importance in technology. The nature of gold is diverse. The chemical element gold is a heavy, soft metal. It weighs nearly twice as much as lead. Shiny and deep yellow in color, gold is one of two metals, which are not gray or white when pure. Gold is the most ductile of metals. Properties of gold are: ? Symbol - Au ? Atomic Number – 79 ? Atomic Weight – 196.967 ? Electron Configuration - -32-18-1 ? Group in Periodic Table – 1B ? Density at 68 F – 19.3 g/cm^3 ? Boiling Point – 5,370.8 F ? Melting Point – 1,945.4 F ? Number of Protons/Electrons – 79 ? Number of Neutrons – 118 ? Classification – Transition Metal ? Crystal Structure – Cubic Facts: ? Date of Discovery – Circa 3000 BC ? Discover – Unknown ? Name of Origin – From the Old English word geolo (yellow) ? Symbol Origin – From the Latin word aurum (gold) ? Uses – electronics, jewelry, coins ? Obtained From – crust of the earth, copper ores Atomic and Chemical Properties: In it’s usual state – atomic mass number 197 – gold is stable. However, there are radioactive (unstable) isotopes of mass number 186 to 196 and 198 to 203. Gold normally exhibits a chemical valence of one or three. Gold is the “noblest'; of the noble metals (gold, platinum, palladium, and rhodium), so termed because of their inertness, or reluctance to enter into chemical reactions. Gold will not react with common acids but is attacked by a three-to-one mixture of hydrochloric and nitric acids. This combination is called aqua regia because it reacts with the so-called royal metal. Gold will not combine directly with oxygen, but oxides may be formed indirectly. Gold will also combine with the halogens (fluorine, chlorine bromine, and iodine) and with the cyanides. The purity of gold is expressed in Karats (KT), on a scale of 24, or in fineness, on a scale of 1,000. Pure gold is 24 Karat or 1,000 fine. An alloy containing 75 percent gold would be described as 18- Karat gold or 750 fine. History: (Sanskrit Jval; Anglo – Saxon gold; L. aurum, gold) Known and highly valued from earliest times, gold is found in nature as the free metal and in tellurides; it is very widely distributed and is almost always associated with quarts or pyrite.

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