Co 鈷 27 58.933195 9 4 d 27 1495.0 2870.0 [Ar] 3d7 4s2 2 8 15 2 8.9 0.003% Gray Hexagonal 1.9 1.84 {"1":"760.4","2":"1648","3":"3232","4":"4950","5":"7670","6":"9840","7":"12440","8":"15230","9":"17959","10":"26570","11":"29400","12":"32400","13":"36600","14":"39700","15":"42800","16":"49396","17":"52737","18":"134810","19":"145170","20":"154700","21":"167400","22":"178100","23":"189300","24":"204500","25":"214100","26":"920870","27":"966023"} 761 63.7 126 +2,3 1.25 6.7 16.19 373.3 0.421 100.0 0 Solid, Ferromagnetic, Conductor, TransitionMetal, Metal, Stable, Natural KO-bolt Hard, ductile, lustrous bluish-gray metal. Exists in the earth's curst in cocentrations of about 25 ppm. It has remarkable magnetic properties. Used in many hard alloys; for magnets, ceramics and special glasses. Remains hard up to 982°C. Radioactive cobalt-60 is used in cancer therapy. Occurs in compounds with arsenic, oxygen and sulfur as in cobaltine (CoAsS) and linneite (Co3S4). Pure cobalt is obtained as a byproduct of refining nickel, copper and iron. V6ljxByu9ng Cobalt

大约1630年，氯气就被比利时化学家和物理学家詹 巴皮斯托 范赫尔穆特发现

1774年瑞典化学家卡尔威赫姆舍勒首先制备并学习了氯单质

1810年之前，科学界都认为其是氧化的盐酸

但是1811年汉弗莱 戴维总结认为这种新气体是一种新元素 希腊文“发绿的黄” 27 1735 Georg Brandt Sweden From the German word "kobald" meaning "goblin" or evil spirit

单质氯在高浓度情况下是及其危险和有毒的

树蛙皮肤中的氯化合物是一种强有力的镇痛药

氯被用在饮水消毒

它被广泛用在纸张生产，染料，纺织，石油产品，药品，防腐剂，杀虫剂，食品，溶剂，画作，塑料，及其他消费品

氯化物被大范围地用作消毒，木浆漂白，灭菌，和纺织过程