Half-lives of The Highest-numbered Elements
All elements with an atomic number above 82 (lead) are unstable, and the "stability" (half-life of the longest-lived known isotope) of elements generally decreases with rising atomic numbers from the relatively stable uranium (92) upwards to the heaviest known element: 118. It increases very slightly in the range of elements 110 to 113, hypothesized to be at the beginning of the island of stability. The longest-lived observed isotopes of each of the heaviest elements are shown in the following table.
| Number | Name | Longest-lived isotope |
Half-life | Article |
|---|---|---|---|---|
| 100 | Fermium | 257Fm | 8,70,000 ! 101 days | Isotopes of fermium |
| 101 | Mendelevium | 258Md | 4,500,000 ! 52 days | Isotopes of mendelevium |
| 102 | Nobelium | 259No | 0,003,500 ! 58 minutes | Isotopes of nobelium |
| 103 | Lawrencium | 262Lr | 0,013,000 ! 3.6 hours | Isotopes of lawrencium |
| 104 | Rutherfordium | 267Rf | 0,004,700 ! 1.3 hours | Isotopes of rutherfordium |
| 105 | Dubnium | 268Db | 0,104,000 ! 29 hours | Isotopes of dubnium |
| 106 | Seaborgium | 271Sg | 0,000,110 ! 1.9 minutes | Isotopes of seaborgium |
| 107 | Bohrium | 270Bh | 0,000,061 ! 61 seconds | Isotopes of bohrium |
| 108 | Hassium | 277mHs | 0,001,000 ! ~12 minutes | Isotopes of hassium |
| 109 | Meitnerium | 278Mt | 0,000,008 ! 7.6 seconds | Isotopes of meitnerium |
| 110 | Darmstadtium | 281Ds | 0,000,011 ! 11 seconds | Isotopes of darmstadtium |
| 111 | Roentgenium | 281Rg | 0,000,022.8 ! 26 seconds | Isotopes of roentgenium |
| 112 | Copernicium | 285Cn | 0,000,029 ! 29 seconds | Isotopes of copernicium |
| 113 | Ununtrium | 286Uut | 0,000,019.6 ! 19.6 seconds | Isotopes of ununtrium |
| 114 | Flerovium | 289Fl | 0,000,002.6 ! 2.6 seconds | Isotopes of flerovium |
| 115 | Ununpentium | 289Uup | 0,000,000.220 ! 220 milliseconds | Isotopes of ununpentium |
| 116 | Livermorium | 293Lv | 0,000,000.061 ! 61 milliseconds | Isotopes of livermorium |
| 117 | Ununseptium | 294Uus | 0,000,000.078 ! 78 milliseconds | Isotopes of ununseptium |
| 118 | Ununoctium | 294Uuo | 0,000,000.000,89 ! 0.89 milliseconds | Isotopes of ununoctium |
For comparison, the shortest-lived element with atomic number below 100 is francium (element 87) with a half-life of 22 minutes.
The half-lives of nuclei in the island of stability itself are unknown since none of the isotopes that would be "on the island" have been observed. Many physicists think they are relatively short, on the order of minutes or days. Some theoretical calculations indicate that their half-lives may be long, on the order of 109 years.
The alpha-decay half-lives of 1700 nuclei with 100 ≤ Z ≤ 130 have been calculated in a quantum tunneling model with both experimental and theoretical alpha-decay Q-values. The theoretical calculations are in good agreement with the available experimental data.
A possible stronger decay mode for the heaviest superheavies was shown to be cluster decay by Dorin N Poenaru, R.A. Gherghescu, Walter Greiner.
Read more about this topic: Island Of Stability
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