Radium, the atom ordinal number 88, atomic weight 2260254, is a kind of natural radio chemical element, the chemical element comes from Latin text, the original intention is" shoot the line".Resided the mile in 1898, the husband and wife discovered the radium from the asphalt uranium mineral mineral 渣 , separating 90 milligram chlorination radiums of in 1902, the first step measuresed the atomic weight of the radium.The radium distributes in the nature very widely, but the content is very tiny, content in the earth crust for 1/1,000,000,000, the total amount is about 18,000,000 tons.Have already discover now all isotopes of the radium that quantity counts to 206-230, among them only have the radium 223,224,226 and 228 is a natural radioisotope, the rest is all to respond through the artificial pit to synthesize of.226 half- lifes of radium are most long, the natural and plentiful degree is biggest, is the most important isotope of radium. The radium is a white and glossy metals of silver, the 熔 orders 700 ° Cs,1140 ° Cs of boiling point, density about 5 the grams/ 厘s rices 3, the body heart signs the square space of 晶 .The chemistry property of the radium is cheery, with the barium likeness.The metals radium expose up in the air ability quick reaction, the born oxide and nitrogens turn the thing;Can respond the born hydrogen with water to oxidize the radium;New-made the radium salt that have presents the white, changing countenance after place because of is shine on by 辐 . The radium is a modern pit the industry rise front the most important radio material, be apply in the medical treatment, industry and research realms extensively;Make the radium salt and the vulcanized zinc fluorescence powder mix evenly, can into the permanence gives out light the powder.Up to 1975, the total gave birth to of whole world is about 4,000 grams of radiums, among them,85% useds for the medical treatment,10% uses to make to give out light the powder.The radium is a deadly poison material.镭,原子序数88,原子量2260254,是一种天然放射性元素,元素名来源于拉丁文,原意是“射线”。1898年居里夫妇从沥青铀矿矿渣中发现了镭,1902年分离出90毫克氯化镭,初步测定了镭的原子量。镭在自然界分布很广,但含量极微,地壳中的含量为十亿分之一,总量约1800万吨。现已发现质量数为206~230的镭的全部同位素,其中只有镭223、224、226、228是天然放射性同位素,其余都是通过人工核反应合成的。镭226半衰期最长,天然丰度最大,是镭的最重要的同位素。 镭是银白色有光泽的金属,熔点700°C,沸点1140°C,密度约5克/厘米3,体心立方晶格。镭的化学性质活泼,与钡相似。金属镭暴露在空气中能迅速反应,生成氧化物和氮化物;能与水反应生成氢氧化镭;新制备的镭盐呈白色,放置后因受辐照而变色。 镭是现代核工业兴起前最重要的放射性物质,广泛应用于医疗、工业和科研领域;把镭盐和硫化锌荧光粉混匀,可制成永久性发光粉。到1975年为止,全世界共生产了约4千克镭,其中85%用于医疗,10%用来制造发光粉。镭是剧毒物质。