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111
Rg
281

Roentgenium

Unknown Group 11 Period 7 Block d

Roentgenium is a chemical element of the periodic table with chemical symbol Rg and atomic number 111 with an atomic weight of 281 u and is classed as unknown and is part of group 11 (coinage metals). Roentgenium is solid at room temperature.

Roentgenium in the periodic table

SymbolRg
Atomic number111
Group11 (Coinage metals)
Period7
Blockd
ClassificationUnknown
Appearance-
Color-
Number of protons111 p+
Number of neutrons170 n0
Number of electrons111 e-
From Wikipedia, the free encyclopediaRoentgenium is a chemical element with symbol Rg and atomic number 111. It is an extremely radioactive synthetic element (an element that can be created in a laboratory but is not found in nature); the most stable known isotope, roentgenium-282, has a half-life of 2.1 minutes. Roentgenium was first created in 1994 by the GSI Helmholtz Centre for Heavy Ion Research near Darmstadt, Germany.

Physical properties

Phase at STPSolid
Density28.7 g/cm3
Atomic weight281 u

Atomic properties

Electronegativity (Pauling Scale)-
Electron affinity151 kJ/mol
Oxidation states(−1), (+1), (+3), (+5), (+7)
(predicted)
Ionization energies
  1. 1022.7 kJ/mol
  2. 2074.4 kJ/mol
  3. 3077.9 kJ/mol
  4. 4052.4 kJ/mol
  5. 5306.7 kJ/mol

Electron configuration for roentgenium

Electron configuration
Shorthand configuration
[Rn] 5f14 6d9 7s2
Full configuration1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f14 6s2 6p6 6d9 7s2
Electron configuration chart
1s2
2s22p6
3s23p63d10
4s24p64d104f14
5s25p65d105f14
6s26p66d9
7s2
Electrons per shell2, 8, 18, 32, 32, 17, 2
Valence electrons 11
Valency electrons
Bohr model
RoentgeniumElectron shell for Roentgenium, created by Injosoft ABRg
Figure: Shell diagram of Roentgenium (Rg) atom.
Orbital Diagram
1s
2s2p
3s3p3d
4s4p4d4f
5s5p5d5f
6s6p6d
7s

The history of Roentgenium

DiscoveryGesellschaft für Schwerionenforschung (1994)
Named byGSI
Discovery of roentgenium
Roentgenium was first synthesized in December 1994 at GSI in Darmstadt by the team of Sigurd Hofmann using cold fusion of nickel-64 ions with bismuth-209. The element was named in honour of Wilhelm Conrad Röntgen, the German physicist who discovered X-rays in 1895 and received the first ever Nobel Prize in Physics in 1901.
Original wordRöntgen
Language of origin English
Name sourcePerson
Meaning“Wilhelm Röntgen”
Naming
The element is named in honour of Wilhelm Conrad Roentgen, the German physicist who discovered X-rays in 1895.

Identifiers

List of unique identifiers for Roentgenium in various chemical registry databases
CAS Number54386-24-2
ChemSpider ID-
EC number-
PubChem CID Number135476786