1 •放射性核素衰变表3h35S32P125【11剩余活性剩余活性剩余活性剩余活性剩余活性时间（年）（%）时间（年）（%）时间（年）（%）时间（年）（%）时间（年）（%）194.5298.4195.3495.50.298.3289.3596.1290.8891.20.496.6384.41092.3386.51287.10.695.0479.81588.7482.51683.11.091.8575.42085.3578.52079.41.687.2671.32582.0674.82475.82.381.2767.43178.1771.22872.43.176.7863.73774.5867.83269.14.071.0960.24371.0964.73666.05.065.21056.95067.01061.24063.06.159.31153.85763.61158.74460.27.353.41250.96559.61255.94857.48.150.012.350.07356.01353.25254.88152.51450.75652.487.150.014.350.06050.02.放射性测定单位单位吸收放射线剂量（拉得定义 换算八 100尔格/克（电离辐射传给单位质量物质的 1rad） 0.87rad=lr能量）伦琴（r）使1克空气产生1.6 x1012离子对的X或Y-射线的照射剂量r/0.87=1rad居里（Ci）每秒放射性衰变3.7 X1010个原子的量1Ci=103mCi=1C F口 Ci毫居（mCi）千分之一居里1mCi=1OaCi=103u Ci微居（n Ci）百万分之一居里（每分钟衰变2.2 x106次）1 n Ci=10-6Ci=10-3MCi伯克莱尔（Bq）每秒衰变1个原子的量1Bq=3.7X10 -Mi千伯克莱尔（kBq）1kBq=10aBq百万伯克莱尔（MBq1MBq=10Bq兆伯克莱尔（GBq1GBq=1(feq每分钟衰变数（dpn） 每分钟衰变的原子数 2.2 X106dpm=1|i Ci每分钟计数（cpm） 测量仪测岀每分钟B粒子数 Cpm=（pmX计数器效率一、原子量符号原子序数89原子量227.02辛阿(actinium )Ac辛吕(aluminium )Al1326.98镅(americium )Am95(243)锑(antimony )Sb51121.75氩(argon)Ar1839.94砷(arsenic )As3374.92砹(astatine )At85(210)钡(barium )Ba56137.33锫(berkelium )Bk97(247)铍(beryllium )Be49.01铋(bismuth )Bi83208.98硼(boron)B510.81溴(bromine )Br3579.90镉(cadmium)Cd48112.41钙(calcium )Ca2040.08锎 1( californium )Cf98(251)碳(carbon )C612.01铈(cerium )Ce58140.12铯(cesium)Cs55132.90氯(chlorine )Cl1735.45铬(chromium)Cr2451.99钻(cobalt )Co2758.93铜(copper)Cu2963.54锔(curium )Cm96(247)镝(dysprosium )Dy66162.50锿(einsteinium )Es99(252)铒(erbium )Er68167.26铕(euroqium )Eu63151.96镄(fermium )Fm100(257)氟(fluorine )F918.99钫(francium )Fr87(223)轧(gadolinium )镓(galium )GdGa6431157.5269.72锗(germanium)Ge3272.59金(gold )Au79196.96铪(hafnium )Hf72178.49氦(helium )He24.00钦(holmium)Ho67164.93氢(hydrogen )H11.00铟 1( indium )In49114.82碘(iodine )I53126.90铱(iridium )Ir77192.22铁(iron )Fe2655.84氟(krypton )Kr3683.80镧(lanthanum )La57139.90镑(Lawrencium)Lr103(260)铅(lead )Pb82207.2锂(lithium )Li36.94镥(lutetium )Lu71174.96镁(Magnesium)Mg1224.30锰(manganse)Mn2554.93钔 1( mendelevium)Md101(258)汞(molybdenum)Hg80200.59钼 1( molybdenum)Mo4295.94钕(neodymium)Nd60144.24氖(neon)Ne1020.17镎(neptunium )Np93237.04镍(nickel )Ni2858.69铌(niobium )Nb4192.00氮(nitrogen )N714.00错(nobelium )No102(259)锇(osmium)Os76190.2氧(oxygen)O815.99卡巴(palladium )Pd46106.42磷(phosphorus )P1530.94钋(polonium )Po84(209)钾(potassium )K1939.09错(praseodymium)Pr59140.90钜(promethium )Pm61(145)镤(protactinium )Pa91231.03镭(radium )Ra88226.02氡(radon)Rn86(222)铼(rhenium )Re75186.20铑(rhodium )Rh45102.90铷(rubidium )Rb3785.46钉(ruthenium )Ru44101.07钐(samarium)Sm62150.36钪(scandium)Sc2144.95硒(sillicon )Se3478.96硅( sillicon )Si1428.08银(sliver )Ag47107.86钠(sodium)Na1122.98锶(strontium )Sr3887.62硫( sulfur )S1632.06钽(tantalum )Ta73180.94锝(technetium )Tc43(98)碲(tellurium )Te52127.60铽(terbium )Tb65158.92铊(thallium )Tl81204.38钍(thorium )Th90232.03锡(tin )Sn50118.69铥(thulium )Tm69168.93钛(titanium )Ti2247.88钨(tungsten )W74183.85unhilhexium(Unh)106(263)unnilpentium(Unp)105(262)unnilquadium(Unq)104(261)钚(piutonium )(244)94Pu铂(platium )195.08Pt78unnilseptium(Uns)107(262)铀(uranium )U92238.02钒(vanadium)V2350.94氙(xenon)Xe54131.29镒(ytterbium )Yb70173.04钇(yttrium )Y3988.90锌(zinc)Zn3065.38锆(zirconium )Zn4091.22圆括号中的数字是该元素最稳定的同位素的质量数。