Skip to Main Content

About Roentgenium

Roentgenium Bohr

Roentgenium, a synthetic transactinide (or super heavy element), was first synthesized in 1994 at the Institute for Heavy Ion Research (Gesellschaft für Schwerionenforschung (GSI)) in Darmstadt, Germany. In 2004, IUPAC accepted the GSI’s suggestion of the name roentgenium in honor of Wilhelm Conrad Röntgen. In 1895, Röntgen recognized x-rays as a unique type of rays with special properties that made them uniquely useful in a variety of applications. Roentgenium itself, however, has no commercial applications and much remains unknown about its properties due to its extremely short half-life.

Roentgenium Properties

Roentgenium  Bohr ModelRoentgenium is a D-Block, Group 11, Period 7 element. The number of electrons in each of Roentgenium's shells is 2, 8, 18, 32, 32, 18, 1 and its electron configuration is [Rn] 5f14 6d10 7s1. In its elemental form, Roentgenium's CAS number is 54386-24-2. Roentgenium was discovered in 1994 at the Institute for Heavy Ion Research (Gesellschaft für Schwerionenforschung (GSI)) in Darmstadt, Germany by Sigurd Hofmann, Peter Armbruster and Gottfried Münzenberg. Roentgenium is a synthetic element that is not present in the environment. Little is known about the element, its appearance is unknown, and it has no known uses. Roentgenium is named after Wilhelm Röntgen, the physicist who discovered X-rays.

Roentgenium information, including technical data, properties, and other useful facts are specified below. Scientific facts such as the atomic structure, ionization energy, abundance on Earth, conductivity, and thermal properties are included.

Symbol: Rg
Atomic Number: 111
Atomic Weight: 281
Element Category: transition metal
Group, Period, Block: 11, 7, d
Color: unknown (presumably metallic/ silvery white/ gray)
Other Names: Roentgenio
Melting Point: N/A
Boiling Point: N/A
Density: 28.7 (predicted)
Liquid Density @ Melting Point: N/A
Density @ 20°C: N/A
Density of Solid: 24400 (predicted) kg·m3
Specific Heat: N/A
Superconductivity Temperature: N/A
Triple Point: N/A
Critical Point: N/A
Heat of Fusion (kJ·mol-1): N/A
Heat of Vaporization (kJ·mol-1): N/A
Heat of Atomization (kJ·mol-1): N/A
Thermal Conductivity: N/A
Thermal Expansion: N/A
Electrical Resistivity: N/A
Tensile Strength: N/A
Molar Heat Capacity: N/A
Young's Modulus: N/A
Shear Modulus: N/A
Bulk Modulus: N/A
Poisson Ratio: N/A
Mohs Hardness: N/A
Vickers Hardness: N/A
Brinell Hardness: N/A
Speed of Sound: N/A
Pauling Electronegativity: N/A
Sanderson Electronegativity: N/A
Allred Rochow Electronegativity: N/A
Mulliken-Jaffe Electronegativity: N/A
Allen Electronegativity: N/A
Pauling Electropositivity: N/A
Reflectivity (%): N/A
Refractive Index: N/A
Electrons: 111
Protons: 111
Neutrons: 170
Electron Configuration: [Rn] 5f14 6d10 7s1
Atomic Radius: 114 pm (predicted)
Atomic Radius,
non-bonded (Å):
Unknown
Covalent Radius: 121 pm (predicted)
Covalent Radius (Å): 1.21
Van der Waals Radius: N/A
Oxidation States: 5, 3, 1, 1 (predicted)
Phase: Solid
Crystal Structure: unknown
Magnetic Ordering: unknown
Electron Affinity (kJ·mol-1) Unknown
1st Ionization Energy: 1022.7 kJ·mol-1(estimated)
2nd Ionization Energy: 2074.4 kJ·mol-1(estimated)
3rd Ionization Energy: 3077.9 kJ·mol-1(estimated)
CAS Number: 54386-24-2
EC Number: N/A
MDL Number: N/A
Beilstein Number: N/A
SMILES Identifier: N/A
InChI Identifier: N/A
InChI Key: N/A
PubChem CID: N/A
ChemSpider ID: N/A
Earth - Total: N/A
Mercury - Total: N/A
Venus - Total: N/A
Earth - Seawater (Oceans), ppb by weight: N/A
Earth - Seawater (Oceans), ppb by atoms: N/A
Earth -  Crust (Crustal Rocks), ppb by weight: N/A
Earth -  Crust (Crustal Rocks), ppb by atoms: N/A
Sun - Total, ppb by weight: N/A
Sun - Total, ppb by atoms: N/A
Stream, ppb by weight: N/A
Stream, ppb by atoms: N/A
Meterorite (Carbonaceous), ppb by weight: N/A
Meterorite (Carbonaceous), ppb by atoms: N/A
Typical Human Body, ppb by weight: N/A
Typical Human Body, ppb by atom: N/A
Universe, ppb by weight: N/A
Universe, ppb by atom: N/A
Discovered By: Sigurd Hofmann, Peter Armbruster and Gottfried Münzenberg
Discovery Date: 1994
First Isolation: N/A

Roentgenium Isotopes

Roentgenium (Rg) is an artificial element. Like all artificial elements, it has no stable isotopes.

Nuclide Isotopic Mass Half-Life Mode of Decay Nuclear Spin Magnetic Moment Binding Energy (MeV) Natural Abundance
(% by atom)
272Rg 272.15362(36)# 2.0(8) ms [3.8(+14-8) ms] a to 268Mt 5+#,6+# N/A 1933.11 -
273Rg 273.15368(65)# 5# ms Unknown N/A N/A 1941.19 -
274Rg 274.15571(66)# 6.4(+307-29) ms a to 270Mt N/A N/A 1949.27 -
275Rg 275.15614(74)# 10# ms Unknown N/A N/A 1957.35 -
276Rg 276.15849(67)# 100# ms Unknown N/A N/A 1965.43 -
277Rg 277.15952(66)# 1# s Unknown N/A N/A 1973.51 -
278Rg 278.16160(68)# 1# s a to 274Mt N/A N/A 1972.27 -
279Rg 279.16247(71)# 0.17(+81-8) s a to 275Mt N/A N/A 1980.35 -
280Rg 280.16447(80)# 3.6(+43-13) s a to 276Mt N/A N/A 1988.43 -
281Rg 281.16537(100)# 1# min SF; a to 277Mt N/A N/A 1996.51 -
282Rg 282.16749(95)# 4# min a to 278Mt N/A N/A 2004.59 -
283Rg 283.16842(84)# 10# min Unknown N/A N/A 2012.66 -