Quick answerRoentgenium (Rg) is a transition metal with atomic number 111 and a mass number of 282 (the most stable isotope), in group 11, period 7. It was discovered by Sigurd Hofmann and colleagues in 1994. It is used for superheavy element research and studying relativistic effects. Its electron configuration is [Rn] 5f14 6d9 7s2 (predicted).
Roentgenium is a synthetic element named for Wilhelm Röntgen, discoverer of X-rays, made a few atoms at a time.
Key facts
| Symbol | Rg |
|---|---|
| Atomic number | 111 |
| Atomic mass | [282] — mass number of the most stable isotope |
| Category | transition metal |
| Group | 11 |
| Period | 7 |
| Block | d-block |
| Electron configuration | [Rn] 5f14 6d9 7s2 predicted |
| Discovered | Sigurd Hofmann and colleagues, 1994 |
| Uses | superheavy element research, studying relativistic effects |
Quick quiz
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Keep exploring
- Periodic table — all 118 elements
- Gold (Au) — another transition metal, atomic number 79
- Mercury (Hg) — another transition metal, atomic number 80
- Rutherfordium (Rf) — another transition metal, atomic number 104
- Dubnium (Db) — another transition metal, atomic number 105
- Seaborgium (Sg) — another transition metal, atomic number 106
- Bohrium (Bh) — another transition metal, atomic number 107
- Hassium (Hs) — another transition metal, atomic number 108
- Meitnerium (Mt) — another transition metal, atomic number 109
- Darmstadtium (Ds) — another transition metal, atomic number 110
- Copernicium (Cn) — another transition metal, atomic number 112
- All transition metal elements — on the periodic table
Sources & last updated
- CIAAW — Standard Atomic Weights
- PubChem Periodic Table
- Wikipedia — Timeline of chemical element discoveries
- Wikipedia — Roentgenium
Last updated: . Figures are shown with their year; where sources disagree, the value is left out rather than estimated.