Input interpretation
U-238 (uranium-238)
Natural abundance
99.2742%
Decay properties
half-life | 4.47 Gyr (gigayears) (4.464 to 4.4745 Gyr) mean lifetime | 6.45 Gyr (gigayears) (6.4453 to 6.4552 Gyr) decay constant | 4.916×10^-18 per second specific activity | 12.44 kBq/g (kilobecquerels per gram) width | 3.236×10^-33 eV (electronvolts) decay modes | α (alpha emission) | SF (spontaneous fission) | 2β^- (double beta decay) final decay products | Pb-206 (100%) | Tl-205 (1.9×10^-8) | Pb-208 (2.6×10^-11) | W-184 (9×10^-14) | Yb-168 (5×10^-29) | Er-164 (4×10^-29) | Dy-160 (2×10^-30) | Dy-156 (1×10^-32) | Sm-144 (1×10^-33) | Ce-140 (1×10^-34) | Dy-164 (0) | Er-168 (0) | Gd-156 (0) | Hf-176 (0) | Hf-180 (0) | Sm-152 (0) | Yb-172 (0)
Decay modes
decay mode | α (alpha emission) branching ratio | 100% Q-value | 4.26975 MeV (megaelectronvolts) daughter nuclide | Th-234 decay mode | SF (spontaneous fission) branching ratio | 5.45×10^-7 decay mode | 2β^- (double beta decay) branching ratio | 2.2×10^-12 Q-value | 1.1442 MeV (megaelectronvolts) daughter nuclide | Pu-238
Radiation shielding
lead | 12.3 µm water | 29.8 µm air | 27.1 mm
Decay chain
Decay chain
Mass properties
atomic number (Z) | 92 mass number (A) | 238 neutron number | 146 atomic mass | 238.050788247 u (unified atomic mass units) mass excess | 47.308948 MeV (megaelectronvolts) binding energy per nucleon | 7.57012 MeV (megaelectronvolts)
Mass properties
Nearby isotopes
Nearby isotopes