铜(copper)
化学元素，周期表Ib族金属。化学符号Cu，原子序数29。淡红色，极易延展，是电和热极优良的导体。自然界存在游离金属铜，以化合态存在於辉铜矿、黄铜矿、斑铜矿、赤铜矿、孔雀石和蓝铜矿等矿石中。在海藻灰、珊瑚、人的肝脏，以及许多软体动物和节肢动物中都含铜。铜在青血软体动物和甲壳类动物血青素中，起着和铁在红血动物血红素中相同的输氧作用。世界上所生产的铜主要用於电气工业，其余大部分用来与其他金属形成合金。以铜为主要组分的重要合金有黄铜（铜锌合金）、青铜（铜锡合金）、镍银（铜－锌－镍，无银）。几乎所有货币合金中都含有铜。铜在其化合物中的氧化态通常是＋1和＋2。一价铜化合物包括氧化亚铜（Cu2O），主要用作红色颜料和杀菌剂；氯化亚铜（Cu2Cl2），在许多有机反应中用作催化剂；硫化亚铜（Cu2S），用途极广，可用作石油产品的脱色剂和脱硫剂，肥皂、脂肪和油类的缩合剂等等。二价铜化合物则包括氧化铜（CuO），用作颜料（蓝－绿）、脱色剂和催化剂；氯化铜（CuCl2），是一种催化剂、木材防腐剂、媒染剂、消毒剂、饲料添加剂和颜料；硫酸铜（CuSO4），主要用於农业上作杀虫剂、杀菌剂、饲料添加剂和土壤改良剂。
English version：
copper
Metallic chemical element, one of the transition elements, chemical symbol Cu, atomic number 29. Sometimes found in the free state in nature, it is a reddish metal, very ductile and an unusually good conductor of electricity and heat. Most copper is used by the electrical industries; the remainder is combined with other metals, including brass, bronze, nickel, and silver, to form alloys. Copper is part of nearly all coinage metals. In compounds copper usually has valence 1 (cuprous) or 2 (cupric). Cuprous compounds include cuprous oxide, a red pigment and a fungicide; cuprous chloride, a catalyst for certain organic reactions; and cuprous sulfide, with a variety of uses. Cupric compounds include cupric oxide, a pigment, decolorizing agent, and catalyst; cupric chloride, a catalyst, wood preservative, mordant, disinfectant, feed additive, and pigment; and cupric sulfate, a pesticide, germicide, feed additive, and soil additive. Copper is a necessary trace element in the diet and essential to plant growth; in blue-blooded mollusks and crustaceans it plays the same role in hemocyanin as iron does in hemoglobin.