U-238 vs U-231

U-238 (uranium-238) | U-231 (uranium-231)

U-238 | U-231 99.2742% | 0%

| U-238 | U-231 half-life | 4.47 Gyr (4.464 to 4.4745 Gyr) | 100 h (97.2 to 104 h) mean lifetime | 6.45 Gyr (6.4453 to 6.4552 Gyr) | 140 h (5.6 to 6.27 days) decay constant | 4.916×10^-18 per second | 1.9×10^-6 per second specific activity | 12.44 kBq/g | 5000 TBq/g width | 3.236×10^-33 eV | 1.3×10^-21 eV decay modes | α (alpha emission) | SF (spontaneous fission) | 2β^- (double beta decay) | ϵ (electron capture) | α (alpha emission) final decay products | Pb-206 (100%) | Tl-205 (1.9×10^-6%) | Pb-208 (2.6×10^-9%) | W-184 (9×10^-12%) | Yb-168 (5×10^-27%) | Er-164 (4×10^-27%) | Dy-160 (2×10^-28%) | Dy-156 (1×10^-30%) | Sm-144 (1×10^-31%) | Ce-140 (1×10^-32%) | Dy-164 (0%) | Er-168 (0%) | Gd-156 (0%) | Hf-176 (0%) | Hf-180 (0%) | Sm-152 (0%) | Yb-172 (0%) | Pb-207 (100%) | Tl-205 (9×10^-8%) | Pb-208 (1×10^-12%)

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^-5% decay mode | 2β^- (double beta decay) branching ratio | 2.2×10^-10% Q-value | 1.1442 MeV (megaelectronvolts) daughter nuclide | Pu-238

decay mode | ϵ (electron capture) branching ratio | 100% Q-value | 381.65 keV (kiloelectronvolts) daughter nuclide | Pa-231 decay mode | α (alpha emission) branching ratio | 0.004% Q-value | 5.57628 MeV (megaelectronvolts) daughter nuclide | Th-227

| U-238 lead | 12.3 µm water | 29.8 µm air | 27.1 mm

Decay chain U-238

Decay chain U-231

| U-238 | U-231 atomic number (Z) | 92 | 92 mass number (A) | 238 | 231 neutron number | 146 | 139 atomic mass | 238.050788247 u (unified atomic mass units) | 231.036293704 u (unified atomic mass units) mass excess | 47.308948 MeV (megaelectronvolts) | 33.807368 MeV (megaelectronvolts) binding energy per nucleon | 7.57012 MeV (megaelectronvolts) | 7.613381 MeV (megaelectronvolts)

Mass properties