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Tennessine

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Tennessine, 117Ts
Tennessine
Pronunciation/ˈtɛnəsiːn/[1] ​(TEN-ə-seen)
Appearancesemimetallic (predicted)[2]
Mass number[294] (data not decisive)[a]
Tennessine in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson
At
↑
Ts
↓
—
livermorium ← tennessine → oganesson
Atomic number (Z)117
Groupgroup 17 (halogens)
Periodperiod 7
Block  p-block
Electron configuration[Rn] 5f14 6d10 7s2 7p5 (predicted)[4]
Electrons per shell2, 8, 18, 32, 32, 18, 7 (predicted)
Physical properties
Phase at STPsolid (predicted)[4][5]
Melting point623–823 K ​(350–550 °C, ​662–1022 °F) (predicted)[4]
Boiling point883 K ​(610 °C, ​1130 °F) (predicted)[4]
Density (near r.t.)7.1–7.3 g/cm3 (extrapolated)[5]
Atomic properties
Oxidation statescommon: (none)
(−1), (+5)
Ionization energies
  • 1st: 742.9 kJ/mol (predicted)[6]
  • 2nd: 1435.4 kJ/mol (predicted)[6]
  • 3rd: 2161.9 kJ/mol (predicted)[6]
  • (more)
Atomic radiusempirical: 138 pm (predicted)[5]
Covalent radius156–157 pm (extrapolated)[5]
Other properties
Natural occurrencesynthetic
CAS Number54101-14-3
History
Namingafter Tennessee region
DiscoveryJoint Institute for Nuclear Research, Lawrence Livermore National Laboratory, Vanderbilt University and Oak Ridge National Laboratory (2010)
Isotopes of tennessine
Main isotopes[3] Decay
abun­dance half-life (t1/2) mode pro­duct
293Ts synth 25 ms[3][7] α 289Mc
294Ts synth 51 ms[8] α 290Mc
 Category: Tennessine
| references

Ununseptium (Template:Pron-en[9] oon-oon-SEP-tee-əm) is the temporary name of an undiscovered chemical element with the temporary symbol Uus and atomic number 117. It is the only missing element in period 7 of the periodic table. Since it is placed below the halogens it may share qualities similar to astatine or iodine. The first attempt to synthesize this element is currently underway at the Flerov Laboratory of Nuclear Reactions in Dubna, Russia.

History

Naming

The element with Z=117 is historically known as eka-astatine (see 'eka' terminology). The name ununseptium is a systematic element name, used as a placeholder until the element is discovered, the discovery is acknowledged by the IUPAC, and the IUPAC decides on a name. Usually, the name suggested by the discoverer(s) is chosen.

According to current guidelines from IUPAC, the ultimate name for all new elements should end in "-ium", which means the name for element 117 may end in -ium, not -ine, even if ununseptium turns out to be a halogen.[10]

Current experiments

The team at the Flerov laboratory of nuclear reactions has begun an experiment to synthesize element 117 using the reaction[11][12]

48
20Ca
 + 249
97Bk
 → The element Ununseptium does not exist.* → The element Ununseptium does not exist. + 31
0n
.

The expected cross-section is of the order of ~2 pb. The expected evaporation residues, 293117 and 294117, are predicted to decay via relatively long decay chains as far as isotopes of dubnium or lawrencium.

Future experiments

The team at the GSI in Darmstadt, recently acknowledged as the discoverers of element 112 (see ununbium) have begun experiments aiming towards a synthesis of element 117. The GSI have indicated that if they are unable to acquire any 249Bk from the United States, which is likely given the situation regarding the attempt in Russia, they will study the reaction 244Pu(51V,xn) instead, or possibly 243Am(50Ti,xn).[14]

Isotopes and nuclear properties

Nucleosynthesis

Target-projectile combinations leading to Z=117 compound nuclei

The below table contains various combinations of targets and projectiles which could be used to form compound nuclei with Z=117.

Target Projectile CN Attempt result
208Pb 81Br 289117 Reaction yet to be attempted
232Th 59Co 291117 Reaction yet to be attempted
238U 55Mn 293117 Reaction yet to be attempted
237Np 54Cr 291117 Reaction yet to be attempted
244Pu 51V 295117 Reaction yet to be attempted
243Am 50Ti 293117 Reaction yet to be attempted
248Cm 45Sc 293117 Reaction yet to be attempted
249Bk 48Ca 297117 Sucessful reaction
249Cf 41K 290117 Reaction yet to be attempted

Theoretical calculations

Evaporation residue cross sections

The below table contains various targets-projectile combinations for which calculations have provided estimates for cross section yields from various neutron evaporation channels. The channel with the highest expected yield is given.

DNS = Di-nuclear system; σ = cross section

Target Projectile CN Channel (product) σmax Model Ref
209Bi 82Se 291117 1n (290117) 15 fb DNS [15]
209Bi 79Se 288117 1n (287117) 0.2 pb DNS [15]
232Th 59Co 291117 2n (289117) 0.1 pb DNS [15]
238U 55Mn 293117 2-3n (291,290117) 70 fb DNS [15]
244Pu 51V 295117 3n (292117) 0.6 pb DNS [15]
248Cm 45Sc 293117 4n (289117) 2.9 pb DNS [15]
246Cm 45Sc 291117 4n (287117) 1 pb DNS [15]
249Bk 48Ca 297117 3n (294117) 2.1 pb ; 3 pb DNS [15][16]
247Bk 48Ca 295117 3n (292117) 0.8, 0.9 pb DNS [16][15]

Decay characteristics

Theoretical calculations in a quantum tunneling model with mass estimates from a macroscopic-microscopic model predict the alpha-decay half-lives of isotopes of the element 117 (namely, 289-303117) to be around 0.1–40 ms.[17][18][19]

Chemical properties

Predicted chemical properties

Certain chemical properties, such as bond lengths, are predicted to differ from what one would expect based on periodic trends from the lighter halogens (because of relativistic effects).[20]

References

  1. ^ Ritter, Malcolm (June 9, 2016). "Periodic table elements named for Moscow, Japan, Tennessee". Associated Press. Retrieved December 19, 2017.
  2. ^ 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.
  3. ^ a b c Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
  4. ^ a b c d 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.
  5. ^ a b c d Bonchev, D.; Kamenska, V. (1981). "Predicting the Properties of the 113–120 Transactinide Elements". Journal of Physical Chemistry. 85 (9): 1177–1186. doi:10.1021/j150609a021.
  6. ^ a b c Chang, Zhiwei; Li, Jiguang; Dong, Chenzhong (2010). "Ionization Potentials, Electron Affinities, Resonance Excitation Energies, Oscillator Strengths, And Ionic Radii of Element Uus (Z = 117) and Astatine". J. Phys. Chem. A. 2010 (114): 13388–94. Bibcode:2010JPCA..11413388C. doi:10.1021/jp107411s.
  7. ^ Khuyagbaatar, J.; Yakushev, A.; Düllmann, Ch. E.; et al. (2014). "48Ca+249Bk Fusion Reaction Leading to Element Z=117: Long-Lived α-Decaying 270Db and Discovery of 266Lr". Physical Review Letters. 112 (17): 172501. Bibcode:2014PhRvL.112q2501K. doi:10.1103/PhysRevLett.112.172501. PMID 24836239.
  8. ^ Oganessian, Yu. Ts.; et al. (2013). "Experimental studies of the 249Bk + 48Ca reaction including decay properties and excitation function for isotopes of element 117, and discovery of the new isotope 277Mt". Physical Review C. 87 (5): 054621. Bibcode:2013PhRvC..87e4621O. doi:10.1103/PhysRevC.87.054621.
  9. ^ J. Chatt (1979). "Recommendations for the Naming of Elements of Atomic Numbers Greater than 100". Pure Appl. Chem. 51: 381–384. doi:10.1351/pac197951020381.
  10. ^ Koppenol, W. H. (2002). "Naming of new elements(IUPAC Recommendations 2002)" (PDF). Pure and Applied Chemistry. 74: 787. doi:10.1351/pac200274050787.
  11. ^ New chemical element to be synthesized in Russia
  12. ^ Flerov Lab.
  13. ^ a b sagaidak. "Experiment setting on synthesis of superheavy nuclei in fusion-evaporation reactions. Preparation to synthesis of new element with Z=117" (PDF). Retrieved 2009-07-07.
  14. ^ Toward element 117
  15. ^ a b c d e f g h i Zhao-Qing, Feng (2007). "Possible Way to Synthesize Superheavy Element Z = 117". Chinese Physics Letters. 24: 2551. doi:10.1088/0256-307X/24/9/024.
  16. ^ a b Feng, Z (2009). "Production of heavy and superheavy nuclei in massive fusion reactions". Nuclear Physics A. 816: 33. doi:10.1016/j.nuclphysa.2008.11.003.
  17. ^ C. Samanta, P. Roy Chowdhury and D.N. Basu (2007). "Predictions of alpha decay half lives of heavy and superheavy elements". Nucl. Phys. A. 789: 142. doi:10.1016/j.nuclphysa.2007.04.001.
  18. ^ P. Roy Chowdhury, C. Samanta, and D. N. Basu (2008). "Search for long lived heaviest nuclei beyond the valley of stability". Phys. Rev. C. 77: 044603. doi:10.1103/PhysRevC.77.044603.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  19. ^ P. Roy Chowdhury, C. Samanta, and D. N. Basu (2008). "Nuclear half-lives for α -radioactivity of elements with 100 ≤ Z ≤ 130". At. Data & Nucl. Data Tables. 94: 781–806. doi:10.1016/j.adt.2008.01.003.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  20. ^ Trond Saue. "Principles and Applications of Relativistic Molecular Calculations" (PDF)., page 76


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