主要放射性元素一覽

1、主要放射性元素一覽Cs（銫，cesium）Asoft,silvery-whiteductilemetal,liquidatroomtemperature,themostelectropositiveandalkalineoftheelements,usedinphotoelectriccellsandtocatalyzehydrogenationofsomeorganiccompounds.Atomicnumber55;atomicweight132.905;meltingpoint28.5=C;boilingpoint690=C;specificgravity1.87;valence1.銫一

2、種質地柔軟的銀白色韌性金屬，室溫時為液體，為最具正電性與堿性的元素，用作光電池和某些有機化合物氫化作用的催化劑。原子序數(shù)55；原子量132.905；熔點28.5=C；沸點=C；比重1.87；化合價1Sr（鍶，strontium）Asoft,silvery,easilyoxidizedmetallicelementthatignitesspontaneouslyinairwhenfinelydivided.Strontiumisusedinpyrotechniccompoundsandvariousalloys.Atomicnumber38;atomicweight87.62;meltingpo

3、int769=C;boilingpoint1,384=C;specificgravity2.54;valence2.鍶一種銀色易氧化的軟金屬，被分割時能在空氣中自燃。鍶被用于煙火材料的復合物和各種合金。原子序數(shù)為38；原子量為87.62；熔點為769=C；沸點為1,384=C；比重為2.54；化合價為2Ru（釘，ruthenium）Ahardwhiteacid-resistantmetallicelementthatisfoundinplatinumoresandisusedtohardenplatinumandpalladiumforjewelryandinalloysfornonmagne

4、ticwear-resistantinstrumentpivotsandelectricalcontacts.Atomicnumber44;atomicweight101.07;meltingpoint2,310=C;boilingpoint3,900=C;specificgravity12.41;valence0,1,2,3,4,5,6,7,8.釕一種堅硬的白色抗酸金屬元素，在鉑礦中可找到它，用于加固鉑和鈀以制成寶石和化合成非磁性的抗磨損的工具樞紐和電接觸器。原子序數(shù)44；原子量101.07；熔點2,310=C；沸點3,900=C；比重12.41；原子價0,1,2,3,4,5,6,7,8I（

5、碘，iodine）Alustrous,grayish-black,corrosive,poisonoushalogenelementhavingradioactiveisotopes,especiallyI131,usedasamedicaltracerandinthyroiddiseasediagnosisandtherapy.Iodinecompoundsareusedasgermicides,antiseptics,anddyes.Atomicnumber53;atomicweight126.9044;meltingpoint113.5=C;boilingpoint184.35=C;sp

6、ecificgravity（solid,at20=C）4.93;valence1,3,5,7.碘一種有光澤的，灰黑色，具有腐蝕性的，有毒的鹵元素，有放射性同位素，特別是碘131，被用作醫(yī)療上的顯跡物和診斷、醫(yī)治甲狀腺疾病。碘化合物被用作殺菌劑、抗感染劑和染料。原子序數(shù)53；原子重量126.9044；熔點113.5=C；沸點184.35=C；比重（固體，在20=C時）4.93；化合價1，3，5，7See:elementAliquidcontainingiodinedissolvedinethylalcohol,usedasanantisepticforwounds.碘酊；碘酒溶于酒精的碘的一種液

7、體，用作防止傷口感染的藥劑Co（鉆，cobalt）Ahard,brittlemetallicelement,foundassociatedwithnickel,silver,lead,copper,andironoresandresemblingnickelandironinappearance.Itisusedchieflyformagneticalloys,high-temperaturealloys,andintheformofitssaltsforblueglassandceramicpigments.Atomicnumber27;atomicweight58.9332;melting

8、point1,495=C;boilingpoint2,900=C;specificgravity8.9;valence2,3.鈷一種硬而脆的金屬元素，與鎳、銀、鉛、銅和鐵礦石一起存在，外表像鎳和鐵。它主要用于磁合金、高溫合金、以鹽的形式用于藍色玻璃和陶瓷顏料。原子序數(shù)27；原子量58.9332；熔點1,495=C；沸點2,900=C；比重8.9；原子價2,3Ba（鋇，barium）Asoft,silvery-whitealkaline-earthmetal,usedtodeoxidizecopperandinvariousalloys.Atomicnumber56;atomicweight13

9、7.34;meltingpoint725=C;boilingpoint1,140=C;specificgravity3.50;valence2.鋇一種柔軟，銀白色的堿土金屬，用來還原銅并用于各種合金。原子序數(shù)56；原子量137.34；熔點725=C；沸點1,140=C；比重3.50；化合價2Ce（鈰，cerium）Alustrous,iron-gray,malleablemetallicrare-earthelementthatoccurschieflyinthemineralsmonaziteandbastnaesite,existsinfourallotropicstates,isacon

10、stituentoflighterflintalloys,andisusedinvariousmetallurgicalandnuclearapplications.Atomicnumber58;atomicweight140.12;meltingpoint795=C;boilingpoint3,468=C;specificgravity6.67to8.23;valence3,4.鈰一種有光澤、鐵灰色、可延展的金屬稀土元素，主要存在于獨居石和氟碳鈰礦中，以四種同素異形體存在，是輕燧石合金的成分，在冶金和核能工業(yè)上有多種應用。原子序數(shù)58；原子量140.12；熔點795=C；沸點3,468=C；

11、比重6.67至8.23；比重6.67-8.23；化合價3,4See:elementU（鈾，uranium）Aheavysilvery-whitemetallicelement,radioactiveandtoxic,easilyoxidized,andhaving14knownisotopesofwhichU238isthemostabundantinnature.Theelementoccursinseveralminerals,includinguraniniteandcarnotite,fromwhichitisextractedandprocessedforuseinresearch,

12、nuclearfuels,andnuclearweapons.Atomicnumber92;atomicweight238.03;meltingpoint1,132=C;boilingpoint3,818=C;specificgravity18.95;valence2,3,4,5,6.鈾銀白色的重金屬元素，有放射性并且有毒，容易被氧化。已知有14個同位素，其中U238是自然界含量最多的。這種元素存在如瀝青鈾礦和釩鉀鈾礦等幾種礦中，并從中提煉和加工，主要用于研究，核燃料和核武器。原子序數(shù)為92；原子量為238.03；熔點為1,132=C；沸點3,818=C；比重18.95；化合價2，3,4，5，

13、6Pu（钚，plutonium）Anaturallyradioactive,silvery,metallictransuranicelement,occurringinuraniumoresandproducedartificiallybyneutronbombardmentofuranium.Itslongest-livedisotopeisPu244withahalf-lifeof76millionyears.Itisaradiologicalpoison,specificallyabsorbedbybonemarrow,andisused,especiallythehighlyfissi

14、onableisotopePu239,asareactorfuelandinnuclearweapons.Atomicnumber94;meltingpoint640=C;boilingpoint3,235=C;specificgravity19.84;valence3,4,5,6.钚一種天然地放射性銀色超鈾金屬元素，存在于鈾礦中，對鈾元素進行中子轟擊而人工制成。其存在周期最長的同位素是半衰期為七千六百萬年的鈽244，它是一種核輻射毒素，特別是能被骨髓吸收。尤其是其極具可裂變性的同位素鈽239,被用作一種核反應燃料并用在核武器中。原子序數(shù)94；熔點640=C；沸點3,235=C；比重19.84；化合價3,4,5,6Am（镅，americium）Awhitemetallictransuranicelementoftheactinideseries,havingisotopeswithmassnumbersfrom237to246andhalf-livesfrom25minutesto7,950years.Itslongest-livedisoto