Roentgenium - 111Rg: the essentials
- Name: roentgenium
- Symbol: Rg
- Atomic number: 111
- Relative atomic mass (Ar): [ 281 ] (longest lived isotope)
- Standard state: presumably a solid at 298 K
- Appearance: unknown, but probably metallic and silvery white or grey in appearance
- Classification: Metallic
- Group in periodic table: 11
- Group name: (none)
- Period in periodic table: 7
- Block in periodic table: d
- Shell structure: 2.8.18.32.32.18.1
- CAS Registry: 54386-24-2
Roentgenium atoms have 111 electrons and the shell structure is 2.8.18.32.32.18.1. 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: description
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
Melting point: (no data) K
Boiling point: (no data) K
Enthalpy of fusion: 20.5 kJ mol-1
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
Roentgenium: electronegativities
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
Roentgenium: abundances
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.
Roentgenium: uses
Roentgenium: reactions
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: history
Roentgenium 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.Roentgenium: isotopes
Roentgenium: isolation
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.