Common isotopes:Carbon-14 (¹⁴C)5.73e+3 years
Uranium-238 (²³⁸U)4.47e+9 years
Uranium-235 (²³⁵U)7.04e+8 years
Thorium-232 (²³²Th)1.41e+10 years
Potassium-40 (⁴⁰K)1.25e+9 years
Rubidium-87 (⁸⁷Rb)4.88e+10 years
Samarium-147 (¹⁴⁷Sm)1.06e+11 years
Rhenium-187 (¹⁸⁷Re)4.12e+10 years
Lutetium-176 (¹⁷⁶Lu)3.76e+10 years
Iodine-131 (¹³¹I)8.02e+0 years
Cesium-137 (¹³⁷Cs)3.02e+1 years
Strontium-90 (⁹⁰Sr)2.88e+1 years
Cobalt-60 (⁶⁰Co)5.27e+0 years
Tritium (³H)1.23e+1 years
Radon-222 (²²²Rn)3.82e+0 years
Polonium-210 (²¹⁰Po)1.38e+2 years
Radium-226 (²²⁶Ra)1.60e+3 years
Plutonium-239 (²³⁹Pu)2.41e+4 years
Plutonium-240 (²⁴⁰Pu)6.56e+3 years
Americium-241 (²⁴¹Am)4.32e+2 years