| Theoretical element | ||||||
|---|---|---|---|---|---|---|
| Ununennium | ||||||
| Pronunciation | /ˌuːn.uːnˈɛniəm/ | |||||
| Alternative names | element 119, eka-francium | |||||
| Ununennium in the periodic table | ||||||
| ||||||
| Atomic number (Z) | 119 | |||||
| Group | group 1: hydrogen and alkali metals | |||||
| Period | period 8 (theoretical, extended table) | |||||
| Block | s-block | |||||
| Electron configuration | [Og] 8s1 (predicted)[1] | |||||
| Electrons per shell | 2, 8, 18, 32, 32, 18, 8, 1 (predicted) | |||||
| Physical properties | ||||||
| Phase at STP | unknown phase (could be solid or liquid)[1] | |||||
| Melting point | 273–303 K (0–30 °C, 32–86 °F) (predicted)[1] | |||||
| Boiling point | 903 K (630 °C, 1166 °F) (predicted)[2] | |||||
| Density (near r.t.) | 3 g/cm3 (predicted)[1] | |||||
| Heat of fusion | 2.01–2.05 kJ/mol (extrapolated)[3] | |||||
| Atomic properties | ||||||
| Oxidation states | common: (none) (+1), (+3), (+5)[1][4] | |||||
| Electronegativity | Pauling scale: 0.86 (predicted)[5] | |||||
| Ionization energies |
| |||||
| Atomic radius | empirical: 240 pm (predicted)[1] | |||||
| Covalent radius | 263–281 pm (extrapolated)[3] | |||||
| Other properties | ||||||
| Crystal structure | body-centered cubic (bcc) (extrapolated)[7] | |||||
| CAS Number | 54846-86-5 | |||||
| History | ||||||
| Naming | IUPAC systematic element name | |||||
| Isotopes of ununennium | ||||||
| Experiments and theoretical calculations | ||||||
Ununennium, also known as eka-francium or element 119, is a hypothetical chemical element; it has symbol Uue and atomic number 119. Ununennium and Uue are the temporary systematic IUPAC name and symbol respectively, which are used until the element has been discovered, confirmed, and a permanent name is decided upon. In the periodic table of the elements, it is expected to be an s-block element, an alkali metal, and the first element in the eighth period. It is the lightest element that has not yet been synthesized.
An attempt to synthesize the element has been ongoing since 2018 in RIKEN in Japan. The Joint Institute for Nuclear Research in Dubna, Russia, plans to make an attempt at some point in the future, but a precise date has not been released to the public. The Heavy Ion Research Facility in Lanzhou, China (HIRFL) also plans to make an attempt. Theoretical and experimental evidence has shown that the synthesis of ununennium will likely be far more difficult than that of the previous elements.
Ununennium's position as the seventh alkali metal suggests that it would have similar properties to its lighter congeners. However, relativistic effects may cause some of its properties to differ from those expected from a straight application of periodic trends. For example, ununennium is expected to be less reactive than caesium and francium and closer in behavior to potassium or rubidium, and while it should show the characteristic +1 oxidation state of the alkali metals, it is also predicted to show the +3 and +5 oxidation states, which are unknown in any other alkali metal.
- ^ a b c d e f Hoffman, Darleane C.; Lee, Diana M.; Pershina, Valeria (2006). "Transactinides and the future elements". In Morss; Edelstein, Norman M.; Fuger, Jean (eds.). The Chemistry of the Actinide and Transactinide Elements (3rd ed.). Dordrecht, The Netherlands: Springer Science+Business Media. ISBN 978-1-4020-3555-5.
- ^ Fricke, B.; Waber, J. T. (1971). "Theoretical Predictions of the Chemistry of Superheavy Elements" (PDF). Actinides Reviews. 1: 433–485. Retrieved 7 August 2013.
- ^ a b Bonchev, Danail; Kamenska, Verginia (1981). "Predicting the Properties of the 113–120 Transactinide Elements". Journal of Physical Chemistry. 85 (9). American Chemical Society: 1177–1186. doi:10.1021/j150609a021.
- ^ Cao, Chang-Su; Hu, Han-Shi; Schwarz, W. H. Eugen; Li, Jun (2022). "Periodic Law of Chemistry Overturns for Superheavy Elements". ChemRxiv (preprint). doi:10.26434/chemrxiv-2022-l798p. Retrieved 16 November 2022.
- ^ Pershina, V.; Borschevsky, A.; Anton, J. (20 February 2012). "Fully relativistic study of intermetallic dimers of group-1 elements K through element 119 and prediction of their adsorption on noble metal surfaces". Chemical Physics. 395. Elsevier: 87–94. Bibcode:2012CP....395...87P. doi:10.1016/j.chemphys.2011.04.017. This article gives the Mulliken electronegativity as 2.72, which has been converted to the Pauling scale via χP = 1.35χM1/2 − 1.37.
- ^ Fricke, Burkhard (1975). "Superheavy elements: a prediction of their chemical and physical properties". Recent Impact of Physics on Inorganic Chemistry. Structure and Bonding. 21: 89–144. doi:10.1007/BFb0116498. ISBN 978-3-540-07109-9. Retrieved 4 October 2013.
- ^ Seaborg, Glenn T. (1969). "Prospects for further considerable extension of the periodic table" (PDF). Journal of Chemical Education. 46 (10): 626–634. Bibcode:1969JChEd..46..626S. doi:10.1021/ed046p626. Retrieved 22 February 2018.