definition of physical and chemical properties:
Gold is a metallic chemical symbol (Au), one of the elements known since antiquity. It was possession of gold, turquoise, yellow, bright and attractive sign of wealth for thousands of years.
A shiny yellow metal in the form of blocks can reflect the light seems Cefaiha tortillas green or blue. The gold section Tkotaia accurate - is characterized by painted metal - while there are other types of gold ranging in color from ruby and purple.
The gold in the transition team No. 1 (b) of the periodic table of chemical elements, and atomic number (79), and mass Agency (196.967), and melt gold at a temperature of (1064) degrees Celsius, and boils at (2856) degrees Celsius, and gold a good conductor of heat and electricity.
The pure gold of the most viable types of metal for roads and clouds, where you can hit him or his ways, even up to the intensity (0.000013) cm. Can also form a golden wire length (100) km from the amount of $ (29) grams. Gold and one of the most metal soft bodied, with a hardness of (2.5) to (3) on a scale of hardness.
And gold of a very noble metal is not affected by air or heat or humidity. And dissolves in concentrated mineral acids known, such as hydrochloric acid, and sulfuric, phosphoric, and nitric acid but dissolves in aqua regia (a mixture of hydrochloric and nitric acid centers).
The importance of gold:
He knew the gold and its value has emerged since ancient times, easily formed metal more than any other metal. In addition to the easy availability of gold in its pure form. The beauty of gold and luster, and resistance to corrosion of metals has made him outstanding in the various arts and crafts since ancient times. Given the relative rarity of gold has been used as currency and the basis for international

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