LEAD |
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Lead is a chemical element in the periodic table that has the symbol Pb (L. plumbum) and atomic number 82. A soft, heavy, toxic and malleable poor metal, lead is bluish white when freshly cut but tarnishes to dull gray when exposed to air. Lead is used in building construction, lead-acid batteries, bullets and shot, and is part of solder, pewter, and fusible alloys. Lead has the highest atomic number of all stable elements. (But see the article on Bismuth, which has a half life so long it can be considered stable.)
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MINING (ORES, PROCESSING) |
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Mining is the extraction of valuable minerals or other geological materials from the earth, usually (but not always) from an ore body, vein, or (coal) seam. Materials recovered by mining include bauxite, coal, diamonds, iron, precious metals, lead, limestone, nickel, phosphate, rock salt, tin,uranium, and molybdenum. Any material that cannot be grown from agricultural processes must be mined. Mining in a wider sense can also include extraction of petroleum, natural gas, and even water.
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TECHNOLOGY |
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Technology is a word with origins in the Greek "technologia" ("τεχνολογία") "techne", "τέχνη" ("craft") and "logia", "λογία" ("saying")." "Technology" is a broad term dealing with the use and knowledge of humanity's tools and crafts.
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