Oganesson

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properties
General
Name , symbol , atomic number Oganesson, Og, 118
Element category
Group , period , block 18 , 7 , p
CAS number 54144-19-3
Atomic
Atomic mass 294 and
Electron configuration [ Rn ] 5 f 14 6 d 10 7 s 2 7 p 6
1. Ionization energy 839 kJ / mol
Physically
Isotopes
isotope NH t 1/2 ZA ZE (M eV ) ZP
294 Og {syn.} 0.89  ms α 11.65 290 Lv
For other isotopes see list of isotopes
Hazard and safety information
Radioactive
Radioactive
GHS hazard labeling
no classification available
As far as possible and customary, SI units are used.
Unless otherwise noted, the data given apply to standard conditions .

Oganesson is a chemical element and, as of 2020, had the highest proven atomic number 118. Its element symbol is Og. It is in the 18th  IUPAC group in the periodic table of the elements and thus belongs to the noble gases. Whether it also behaves like a noble gas cannot be definitely clarified as of January 2020, as the chemical properties of the oganesson are still unknown. Its name is derived from its co-discoverer Juri Oganesjan .

In the periodic table it stands between 117 Tenness (first synthesized in 2010) and the hypothetical 119 Ununennium (synthesis not yet successful).

History and synthesis

Alleged production in Berkeley

A report on the generation of elements 116 and 118 at the Lawrence Berkeley National Laboratory was published in the 1999 journal Physical Review Letters . In the following year, the report was withdrawn because the results described could not be reproduced by other scientists. In June 2002, the director of Berkeley Labs announced that the original publication was based on, most likely, falsified data. The employee Victor Ninov was suspected of manipulating decay readings. Ninov, however, declared the measuring apparatus to be faulty and insisted on his innocence.

Production in Dubna

In 2006 the production of element 118 was announced again. Some atoms of the element were produced in Dubna as part of a collaboration between the United Institute for Nuclear Research and the Lawrence Livermore National Laboratory by bombarding californium with calcium ions. They could be identified by their alpha decay products.

The synthesis was carried out by:

Naming

The element initially had the systematic name Ununoctium (chemical symbol Uuo ). According to reports, the discoverers planned to propose the name Moskowium for the new element, which should then have been confirmed by IUPAC . This term has already been partially used in the media. The American group around Ninov initially planned the name Ghiorsium in honor of their colleague Albert Ghiorso , who played a decisive role in the discovery of the elements 95 to 106 . However, the proposal became obsolete after the research results were rejected.

On December 30, 2015, the discovery of the element was officially recognized by IUPAC and the joint venture was granted naming rights. On June 8, 2016, the IUPAC announced that the name Oganesson (Og) had been proposed for the element after the scientific director of the Russian institute and co-discoverer of the element Yuri Z. Oganesjan ; an objection period ended on November 8, 2016. On November 30, 2016, the official designation of Oganesson was announced. Element 115 was also named with Moscovium (Mc).

The ending -on was chosen in analogy to the names of the five noble gases in the periodic table above. Helium, at the top of the column, is the exception.

properties

294 Og is radioactive and very short-lived with a half-life of 0.89 ms. Through alpha decay, Oganesson decays into the element Livermorium , which decays further in milliseconds. It is one of the transactinoids and chemically belongs to the group of noble gases. The physical state of Oganesson is unknown. Oganesson lies in the periodic table on the diagonal border to the semimetals . The halogen astatine , which is also located on this diagonal, has the solid state of aggregation and is rather metallic in appearance. Like 294 Ts, the heavier isotope 294 Og has the highest experimentally proven mass number .

So far there are no experimental findings on the chemical properties of Oganesson, as the element was only detected indirectly on the basis of its typical decay products.

Calculated atomic and physical properties

Due to relativistic effects , Oganesson may not behave like a noble gas ; however, this property is more likely to be expected of Copernicium (element 112). On the other hand, Copernicium behaves chemically similar to mercury .

Og is the only Group 18 element that has a positive electron affinity and would therefore be chemically reactive. Furthermore, an extraordinarily strong spin-orbit coupling occurs in the oganesson atom ( more than 10 eV in the 7p valence orbital ), which leads to a loss of the external electron shell structure. This in turn means that the outer electrons of Og are more reminiscent of a uniform electron gas ( Fermi gas ); this suggests an extremely high polarizability and a high melting point . Furthermore, it was recently calculated that crystalline Og has a very small band gap of only 1.0–1.5 eV and is therefore a semiconductor in contrast to all other noble gas crystals .

Web links

Commons : Oganesson  - album with pictures, videos and audio files
Wiktionary: Oganesson  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. ↑ Entry on oganesson at WebElements, https://www.webelements.com , accessed on June 13, 2020.
  2. ↑ The hazards emanating from radioactivity do not belong to the properties to be classified according to the GHS labeling. With regard to other hazards, this element has either not yet been classified or a reliable and citable source has not yet been found.
  3. ↑ Klaus Roth : Is element 118 a noble gas? In: Chemistry in Our Time . tape 51 , no. 6 , December 2017, p. 418-426 , doi : 10.1002 / ciuz.201700838 .
  4. ↑ Victor Ninov, KE Gregorich, W. Loveland, A. Ghiorso, DC Hoffman, DM Lee, H. Nitsche, WJ Swiatecki, UW Kirbach, CA Laue, JL Adams, JB Patin, DA Shaughnessy, DA Strellis, PA Wilk: Observation of Superheavy Nuclei Produced in the Reaction of 86 Kr with 208 Pb . In: Physical Review Letters . tape 83 , no. 6 , August 1999, p. 1104–1107 , doi : 10.1103 / PhysRevLett.83.1104 (English, freely available online through nuclear.ucdavis.edu [PDF; 83 kB ]).
  5. ↑ Results of Element 118 Experiment Retracted. Berkeley Lab press release . In: www2.lbl.gov. July 27, 2001, accessed August 5, 2018 .
  6. ↑ Victor Ninov, KE Gregorich, W. Loveland, A. Ghiorso, DC Hoffman, DM Lee, H. Nitsche, WJ Swiatecki, UW Kirbach, CA Laue, JL Adams, JB Patin, DA Shaughnessy, DA Strellis, PA Wilk: Editorial Note: Observation of Superheavy Nuclei Produced in the Reaction of 86 Kr with 208 Pb [Phys. Rev. Lett. 83, 1104 (1999)] . In: Physical Review Letters . tape 89 , no. 3 , July 2002, p. 039901 , doi : 10.1103 / PhysRevLett.89.039901 (English).
  7. ↑ Yuri Ts. Oganessian, VK Utyonkov, Yu. V. Lobanov, F. Sh. Abdullin, AN Polyakov, RN Sagaidak, IV Shirokovsky, Yu. S. Tsyganov, AA Voinov, GG Gulbekian, SL Bogomolov, BN Gikal, AN Mezentsev, S. Iliev, VG Subbotin, AM Sukhov, K. Subotic, VI Zagrebaev, GK Vostokin, MG Itkis, KJ Moody, JB Patin, DA Shaughnessy , MA Stoyer, NJ Stoyer, PA Wilk, JM Kenneally, JH Landrum, JF Wild, RW Lougheed: Synthesis of the isotopes of elements 118 and 116 in the 249 Cf and 245 Cm + 48 Ca fusion reactions . In: Physical Review C . tape 74 , no. 4 , October 2006, p. 044602 , doi : 10.1103 / PhysRevC.74.044602 (English).
  8. ↑ Phil Schewe, Ben Stein, Davide Castelvecchi: Elements 116 and 118 Are Discovered. In: Physics news Update 797. American Institute of Physics , October 16, 2006, archived from the original on December 3, 2013 ; accessed on August 5, 2018 .
  9. ↑ Russia, US scientists produce new element. ITAR-TASS press release . October 17, 2006, archived from the original on October 22, 2006 ; accessed on August 5, 2018 .
  10. ^ Discovery and Assignment of Elements with Atomic Numbers 113, 115, 117 and 118. In: IUPAC | International Union of Pure and Applied Chemistry . December 30, 2015, accessed August 5, 2018 .
  11. ↑ a b IUPAC is naming the four new elements nihonium, moscovium, tennessine, and oganesson. In: IUPAC | International Union of Pure and Applied Chemistry . June 8, 2016, accessed August 5, 2018 .
  12. ^ IUPAC Announces the Names of the Elements 113, 115, 117, and 118. In: IUPAC | International Union of Pure and Applied Chemistry . November 30, 2016, accessed August 5, 2018 .
  13. ↑ Jan Dönges: The four new ones have a name. In: Spektrum.de . June 9, 2016, accessed August 5, 2018 .
  14. ↑ Beat Gerber: Super-Heavy Element 112 chemically investigated - experimentally landed on the island of artificial elements. Press release from the Paul Scherrer Institute . In: idw-online.de. Science Information Service , May 31, 2006, accessed on August 5, 2018 .
  15. ↑ Ephraim Eliav, Uzi Kaldor, Yasuyuki Ishikawa, Pekka Pyykkö: Element 118: The First Rare Gas with an Electron Affinity . In: Physical Review Letters . tape 77 , no. 27 , December 30, 1996, pp. 5350–5352 , doi : 10.1103 / PhysRevLett.77.5350 (English, freely available online through researchgate.net ).
  16. ↑ Igor Goidenko, Leonti Labzowsky, Ephraim Eliav, Uzi Kaldor, Pekka Pyykkö: QED corrections to the binding energy of the eka-radon (Z = 118) negative ion . In: Physical Review A . tape 67 , no. 2 , February 28, 2003, p. 020102 , doi : 10.1103 / PhysRevA.67.020102 (English, freely available online through researchgate.net ).
  17. ^ Ephraim Eliav, Stephan Fritzsche, Uzi Kaldor: Electronic structure theory of the superheavy elements . In: Nuclear Physics A . tape 944 , December 2015, p. 518–550 , doi : 10.1016 / j.nuclphysa.2015.06.017 (English, Accepted Manuscript freely available through researchgate.net ).
  18. ↑ Paul Jerabek, Bastian Schuetrumpf, Peter Schwerdtfeger, Witold Nazarewicz: Electron Nucleon and Localization Functions of Oganesson: Approaching the Thomas-Fermi limit . In: Physical Review Letters . tape 120 , no. 5 , January 2018, p. 053001 , doi : 10.1103 / PhysRevLett.120.053001 , arxiv : 1707.08710 , bibcode : 2017arXiv170708710J (English).
  19. ↑ Jan-Michael Mewes, Paul Jerabek, Odile R. Smits, Peter Schwerdtfeger: Oganesson Is a Semiconductor: On the Relativistic Band-Gap Narrowing in the Heaviest Noble-Gas Solids . In: Angewandte Chemie International Edition . tape 58 , no. 40 , 2019, doi : 10.1002 / anie.201908327 .