Table 2.
Selected isotope mass existing at specified time
| Isotope | Initial mass, g | Mass at 1.5 × 109 years, g | Mass at 3.0 × 109 years, g | Mass at 4.5 × 109 years, g |
|---|---|---|---|---|
| 230Th | 0.0 | 1.896 × 1014 | 1.160 × 1014 | 6.157 × 1013 |
| 232Th | 0.0 | 2.392 × 1017 | 3.664 × 1017 | 3.896 × 1017 |
| 231Pa | 0.0 | 4.048 × 1013 | 2.100 × 1013 | 1.277 × 1013 |
| 233Pa | 0.0 | 4.696 × 106 | 1.039 × 107 | 1.581 × 107 |
| 232U | 0.0 | 4.339 × 106 | 3.966 × 106 | 3.641 × 106 |
| 233U | 0.0 | 1.011 × 1013 | 2.237 × 1013 | 3.403 × 1013 |
| 234U | 0.0 | 6.209 × 1014 | 3.798 × 1014 | 2.015 × 1014 |
| 235U | 4.867 × 1018 | 8.844 × 1017 | 4.585 × 1017 | 2.782 × 1017 |
| 236U | 0.0 | 5.940 × 1015 | 5.312 × 1015 | 4.941 × 1015 |
| 237U | 0.0 | 3.339 × 105 | 3.533 × 105 | 3.283 × 105 |
| 238U | 1.606 × 1019 | 1.148 × 1019 | 7.024 × 1018 | 3.726 × 1018 |
| 237Np | 0.0 | 3.855 × 1013 | 4.032 × 1013 | 3.911 × 1013 |
| 238Pu | 0.0 | 2.338 × 106 | 4.303 × 106 | 6.296 × 106 |
| 239Pu | 0.0 | 3.969 × 1013 | 4.288 × 1013 | 3.498 × 1013 |
| 240Pu | 0.0 | 4.937 × 107 | 9.399 × 107 | 1.154 × 108 |
| 241Pu | 0.0 | 1.792 × 10−1 | 5.986 × 10−1 | 1.111 × 100 |
| 241Am | 0.0 | 5.402 × 100 | 1.805 × 101 | 3.348 × 101 |