القلب الولهان
موقوف
Gold is a ....llic element with the atomic number 79 and the symbol Au. While the name gold comes from an Old English word meaning yellow, the symbol comes from the Latin aurum, which means “shining dawn.”
On the periodic table of elements, gold is found in Group 11, along with silver, copper, and roentgenium, and in Period 6 between platinum and mercury. It is referred to as a “transition ....l.” Gold is the most malleable, ductile ....l. Described as yellow, gold is one of the so-called precious ....ls, along with gold and silver.
Known from ancient times — along with mercury, sulfur, copper, silver, lead, and tin — gold was used as early as 6000 B.C. Early use included gold jewelry, for example bracelets and rings, as well as ornamentation. Its malleability means that its early use in any practical items was impossible, so its used was restricted to decoration. The civilizations that employed it included the Egyptians, the Greeks, the Mesopotamians, and the Romans.
Gold is found in both lode deposits and placer deposits, and is naturally uncombined. While the largest deposit is to be found in South Africa, deposits of note are also located in Australia, the former Soviet Union, and a number of western states of the United States, including Arizona in the Southwest; California, Montana, and Washington in the Pacific Northwest, and South Dakota in the Midwest.
Although many people many know gold for its use in jewelry — which is how about 65 percent of it is used, gold has a number of other uses. About 25 percent of gold is used in industrial applications in ceramics, electrical, and electronics applications.
منقول