Input interpretation
U-238 U-235 | half-life
Results
U-238 | 4.47 Gyr (gigayears) (4.463 to 4.4745 Gyr) U-235 | 0.704 Gyr (gigayears) (702.1 to 706.8 Myr)
Units
Relative values
| visual | ratios | | comparisons U-235 | | 0.157 | 1 | 84.3% smaller U-238 | | 1 | 6.4 | 540% larger
Decay properties
| U-238 | U-235 half-life | 4.47 Gyr (4.464 to 4.4745 Gyr) | 0.704 Gyr (702.2 to 706.6 Myr) mean lifetime | 6.45 Gyr (6.4453 to 6.4552 Gyr) | 1.02 Gyr (1.014 to 1.019 Gyr) decay constant | 4.916×10^-18 per second | 3.12×10^-17 per second specific activity | 12.44 kBq/g | 79.8 kBq/g width | 3.236×10^-33 eV | 2.05×10^-32 eV decay modes | α (alpha emission) | SF (spontaneous fission) | 2β^- (double beta decay) | α (alpha emission) | SF (spontaneous fission) | ^28Mg (cluster emission) | ^25Ne (cluster emission) | ^20Ne (cluster 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-206 (8×10^-10%) | Pb-208 (1×10^-12%)