Roentgenium: the essentials
Roentgenium atoms have 111 electrons and the shell structure is 220.127.116.11.32.18.1. The ground state electronic configuration of neutral roentgenium is [Rn].5f14.6d10.7s1 (a guess based upon that of gold) and the term symbol of roentgenium is 2S1/2 (a guess based upon guessed electronic structure).
Roentgenium, was discovered on 8th December 1994 at the GSI in Darmstadt, Germany. The interested reader should consult the on-line version of Creating Super Heavy Elements for a fascinating insight into research on "super-heavy" atoms.
Chemically, roentgenium should be in the same group as the elements copper, silver, and gold (Group 11).
Roentgenium: physical properties
- Density of solid: 24400 (predicted) kg m-3
- Molar volume: 12 (rough estimate based upon density estimate) cm3
- Thermal conductivity: (no data) W m‑1 K‑1
Roentgenium: heat properties
Roentgenium: atom sizes
- Atomic radius (empirical): (no data) pm
- Molecular single bond covalent radius: 121 (coordination number 2) ppm
- van der Waals radius: (no data) ppm
- Pauling electronegativity: (no data) (Pauling units)
- Allred Rochow electronegativity: (no data) (Pauling units)
- Mulliken-Jaffe electronegativity: (no data)
Roentgenium: orbital properties
- First ionisation energy: 1023 kJ mol‑1
- Second ionisation energy: (no data) kJ mol‑1
- Third ionisation energy: (no data) kJ mol‑1
- Universe: (no data) ppb by weight
- Crustal rocks: (no data) ppb by weight
- Human: (no data) ppb by weight
Roentgenium: crystal structure
Roentgenium: biological data
- Human abundance by weight: (no data) ppb by weight
Element 111, roentgenium, has no biological role.
Reactions of roentgenium as the element with air, water, halogens, acids, and bases where known.
Roentgenium: binary compounds
Binary compounds with halogens (known as halides), oxygen (known as oxides), hydrogen (known as hydrides), and other compounds of roentgenium where known.
Roentgenium: compound properties
Bond strengths; lattice energies of roentgenium halides, hydrides, oxides (where known); and reduction potentials where known.
Roentgenium: historyRoentgenium was discovered by S. Hofmann, V. Ninov, F. P. Hessberger, P. Armbruster, H. Folger, G. Münzenberg, and others in 1994 at Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, Germany.. Origin of name: the proposed name roentgenium has yet ot be accepted formally, but lies within the long established tradition of naming elements to honour famous scientists. Wilhelm Conrad Roentgen discovered X-rays in 1895.
Isolation: only a few atoms of element 111, roentgenium, have ever been made through a nuclear reaction involving fusion of an isotope of bismuth, 209Bi, with one of nickel, 64Ni.
209Bi + 64Ni → 272Rg + 1n
Isolation of an observable quantity has never been achieved, and may well never be.