Seaborgium
Seaborgium is a synthetic superheavy element notable for an unusual honor: it was the first element ever named after someone who was still alive at the time. Like the other elements at this end of the periodic table, it has no practical use and exists only briefly in particle accelerator experiments.
- Group · Period
- 6 · 7
- At room temp
- solid
- Melts at
- Not yet available
- Density
- Not yet available
- Discovered
- 1974
Uses
Seaborgium has no practical use outside of research. It’s made only a handful of atoms at a time, decays within seconds, and is nowhere near stable or abundant enough for any commercial or industrial role. Its value lies entirely in what it teaches physicists and chemists about how matter behaves at the far reaches of the periodic table.
History
Seaborgium was first reported in 1974 by a joint Berkeley–Livermore team, with researchers at Dubna also contributing earlier related work on elements in this region of the periodic table. It was named in 1994 after Glenn Seaborg, the chemist who had led or co-led the discovery of nearly a dozen elements earlier on this list, including plutonium, americium, and curium. Because Seaborg was still alive at the time, the proposal broke with the convention of only naming elements after deceased scientists, a departure that took until 1997 to be formally accepted.
Fun facts
- Seaborgium was the first element ever named after a living person — physicist Glenn Seaborg, who was still alive when the name was adopted in 1997.
- Seaborg himself had co-discovered many of the actinide elements decades before one was named after him.
- Its most stable known isotopes last only seconds, identified from single-atom decay chains rather than any visible sample of material.
Frequently asked questions
Does seaborgium have any practical use?
No, it has no commercial or industrial application. It's produced only a few atoms at a time in particle accelerators, purely for research into superheavy element physics and chemistry.
Why was naming it after a living person controversial?
Long-standing convention held that elements should only be named after people once their life's work was complete and could be judged in full, so a living namesake was considered premature. The rules were eventually relaxed for seaborgium in recognition of Glenn Seaborg's exceptional, decades-long contribution to discovering the actinide elements himself.
How do scientists confirm an element that only exists for seconds?
Detectors track the specific sequence of radioactive decays each new atom undergoes as it breaks down step by step into lighter, already known elements. That decay chain acts as a unique signature, confirming which element was briefly created even though it's gone almost as soon as it forms.
Isotopes
12 known isotopes
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| Isotope | Natural abundance | Half-life | Decay mode | Mass excess | Binding energy / nucleon | Decay width |
|---|---|---|---|---|---|---|
| Sg-267 | — | 84 s | Spontaneous fission (83%), Alpha decay (17%) | 115,806 keV | 7,327 keV | 5.43 × 10-18 eV |
| Sg-269 | — | 1.3E2 s | Alpha decay (100%), Spontaneous fission (15%) | 119,692 keV | 7,318 keV | 3.51 × 10-18 eV |
| Sg-271 | — | 96 s | Alpha decay (50%), Spontaneous fission (50%) | 124,617 keV | 7,305 keV | 4.75 × 10-18 eV |
Show all 12 isotopes
| Sg-258 | — | 2.5 ms | Spontaneous fission (90%), Alpha decay (20%) | 105,296 keV | 7,342 keV | 1.82 × 10-13 eV |
| Sg-259 | — | 0.29 s | Alpha decay (90%), Spontaneous fission (20%), Electron capture (13%) | 106,519 keV | 7,340 keV | 1.57 × 10-15 eV |
| Sg-260 | — | 3.6 ms | Alpha decay (50%), Spontaneous fission (50%) | 106,547.5 keV | 7,342.56 keV | 1.27 × 10-13 eV |
| Sg-261 | — | 0.23 s | Alpha decay (100%), Spontaneous fission (1%) | 108,005 keV | 7,339.77 keV | 1.98 × 10-15 eV |
| Sg-262 | — | 6.9 ms | Spontaneous fission (78%), Alpha decay (22%) | 108,369.07 keV | 7,341.17 keV | 6.61 × 10-14 eV |
| Sg-263 | — | 1.0 s | Alpha decay (70%), Spontaneous fission (30%) | 110,195 keV | 7,337 keV | 4.56 × 10-16 eV |
| Sg-264 | — | 37 ms | Spontaneous fission (100%), Alpha decay (36%) | 110,783 keV | 7,338 keV | 1.23 × 10-14 eV |
| Sg-265 | — | 14.4 s | Spontaneous fission (50%), Alpha decay (50%) | 112,794 keV | 7,333 keV | 3.17 × 10-17 eV |
| Sg-266 | — | 0.34 s | Spontaneous fission (100%), Alpha decay (18%) | 113,617 keV | 7,332 keV | 1.34 × 10-15 eV |