Roentgenium
Roentgenium is a synthetic superheavy metal, produced one atom at a time in particle accelerator experiments and never found in nature. It lies in group 11 of the periodic table, below gold and silver, and is named after Wilhelm Röntgen, the physicist who discovered X-rays. As with the rest of this region of the periodic table, its chemistry and physical properties are inferred from theory rather than directly measured.
- Group · Period
- 11 · 7
- At room temp
- solid
- Melts at
- Not yet available
- Density
- Not yet available
- Discovered
- 1994
Uses
Roentgenium has no practical, industrial or medical use of any kind. Every atom ever produced has decayed away within a fraction of a second, far too quickly to be gathered or applied to anything. Its only value is scientific — each detected atom helps researchers test theories of nuclear structure and probe the outer limits of the periodic table.
History
Roentgenium was first synthesized in 1994 by researchers at the GSI Helmholtz Centre in Darmstadt, Germany, who fused accelerated nickel nuclei with a bismuth target and identified the element through the radioactive decay chains of the small number of atoms produced. It was named roentgenium in honor of Wilhelm Röntgen, continuing a tradition of naming elements in this region of the periodic table after pioneering physicists. The name was formally adopted by the International Union of Pure and Applied Chemistry in 2004.
Fun facts
- Roentgenium is named after Wilhelm Conrad Röntgen, who discovered X-rays in 1895 and became the first-ever winner of the Nobel Prize in Physics.
- Roentgenium sits directly below gold in the periodic table, leading chemists to predict it may share some of gold's unusual chemical behavior — though this remains largely untested.
- Only a small number of roentgenium atoms have ever been created, each one decaying within a fraction of a second.
Frequently asked questions
Does roentgenium have any real-world use?
No — roentgenium has no commercial, industrial or medical applications. It is produced purely for fundamental nuclear physics research, a single atom at a time.
How is roentgenium made?
Roentgenium is created by accelerating a beam of nuclei to tremendous speed and firing it at a metal target, so that nuclei occasionally fuse together into a single, heavier roentgenium nucleus. Physicists confirm success by detecting the distinctive radioactive decay chain the new atom produces.
Who was roentgenium named after?
Roentgenium honors Wilhelm Conrad Röntgen, the German physicist who discovered X-rays in 1895 — a discovery that transformed medicine and physics alike and earned him the first Nobel Prize in Physics in 1901.
Isotopes
8 known isotopes
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| Isotope | Natural abundance | Half-life | Decay mode | Mass excess | Binding energy / nucleon | Decay width |
|---|---|---|---|---|---|---|
| Rg-281 | — | 15 s | Spontaneous fission (82%), Alpha decay (18%) | 155,333 keV | 7,209 keV | 3.04 × 10-17 eV |
| Rg-282 | — | 100 s | Alpha decay (100%), Spontaneous fission | 157,742 keV | 7,204 keV | 4.56 × 10-18 eV |
| Rg-286 | — | 11 m | Alpha decay (100%), Spontaneous fission (54%) | 166,510 keV | 7,185 keV | 6.91 × 10-19 eV |
Show all 8 isotopes
| Rg-272 | — | 3.8 ms | Alpha decay (100%) | 142,773 keV | 7,227 keV | 1.20 × 10-13 eV |
| Rg-274 | — | 12 ms | Alpha decay (100%) | 144,612 keV | 7,227 keV | 3.80 × 10-14 eV |
| Rg-278 | — | 4.2 ms | Alpha decay (100%), Spontaneous fission | 150,521 keV | 7,218 keV | 1.09 × 10-13 eV |
| Rg-279 | — | 0.09 s | Alpha decay (100%), Spontaneous fission (25%) | 151,721 keV | 7,216 keV | 5.07 × 10-15 eV |
| Rg-280 | — | 4.4 s | Alpha decay (100%) | 153,886 keV | 7,212 keV | 1.04 × 10-16 eV |