Ununpentium

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"Uup" and "UUp" redirect here. For the political party, see Ulster Unionist Party.
"Element 115" redirects here. For fictional and conspiracy references to element 115, see Materials science in science fiction.
Ununpentium   115Uup
General properties
Name, symbol ununpentium, Uup
Pronunciation Listeni/nnˈpɛntiəm/
oon-oon-PEN-tee-əm
Alternative names element 115, eka-bismuth
Ununpentium in the periodic table
Hydrogen (diatomic nonmetal)
Helium (noble gas)
Lithium (alkali metal)
Beryllium (alkaline earth metal)
Boron (metalloid)
Carbon (polyatomic nonmetal)
Nitrogen (diatomic nonmetal)
Oxygen (diatomic nonmetal)
Fluorine (diatomic nonmetal)
Neon (noble gas)
Sodium (alkali metal)
Magnesium (alkaline earth metal)
Aluminium (post-transition metal)
Silicon (metalloid)
Phosphorus (polyatomic nonmetal)
Sulfur (polyatomic nonmetal)
Chlorine (diatomic nonmetal)
Argon (noble gas)
Potassium (alkali metal)
Calcium (alkaline earth metal)
Scandium (transition metal)
Titanium (transition metal)
Vanadium (transition metal)
Chromium (transition metal)
Manganese (transition metal)
Iron (transition metal)
Cobalt (transition metal)
Nickel (transition metal)
Copper (transition metal)
Zinc (transition metal)
Gallium (post-transition metal)
Germanium (metalloid)
Arsenic (metalloid)
Selenium (polyatomic nonmetal)
Bromine (diatomic nonmetal)
Krypton (noble gas)
Rubidium (alkali metal)
Strontium (alkaline earth metal)
Yttrium (transition metal)
Zirconium (transition metal)
Niobium (transition metal)
Molybdenum (transition metal)
Technetium (transition metal)
Ruthenium (transition metal)
Rhodium (transition metal)
Palladium (transition metal)
Silver (transition metal)
Cadmium (transition metal)
Indium (post-transition metal)
Tin (post-transition metal)
Antimony (metalloid)
Tellurium (metalloid)
Iodine (diatomic nonmetal)
Xenon (noble gas)
Caesium (alkali metal)
Barium (alkaline earth metal)
Lanthanum (lanthanide)
Cerium (lanthanide)
Praseodymium (lanthanide)
Neodymium (lanthanide)
Promethium (lanthanide)
Samarium (lanthanide)
Europium (lanthanide)
Gadolinium (lanthanide)
Terbium (lanthanide)
Dysprosium (lanthanide)
Holmium (lanthanide)
Erbium (lanthanide)
Thulium (lanthanide)
Ytterbium (lanthanide)
Lutetium (lanthanide)
Hafnium (transition metal)
Tantalum (transition metal)
Tungsten (transition metal)
Rhenium (transition metal)
Osmium (transition metal)
Iridium (transition metal)
Platinum (transition metal)
Gold (transition metal)
Mercury (transition metal)
Thallium (post-transition metal)
Lead (post-transition metal)
Bismuth (post-transition metal)
Polonium (post-transition metal)
Astatine (metalloid)
Radon (noble gas)
Francium (alkali metal)
Radium (alkaline earth metal)
Actinium (actinide)
Thorium (actinide)
Protactinium (actinide)
Uranium (actinide)
Neptunium (actinide)
Plutonium (actinide)
Americium (actinide)
Curium (actinide)
Berkelium (actinide)
Californium (actinide)
Einsteinium (actinide)
Fermium (actinide)
Mendelevium (actinide)
Nobelium (actinide)
Lawrencium (actinide)
Rutherfordium (transition metal)
Dubnium (transition metal)
Seaborgium (transition metal)
Bohrium (transition metal)
Hassium (transition metal)
Meitnerium (unknown chemical properties)
Darmstadtium (unknown chemical properties)
Roentgenium (unknown chemical properties)
Copernicium (transition metal)
Ununtrium (unknown chemical properties)
Flerovium (post-transition metal)
Ununpentium (unknown chemical properties)
Livermorium (unknown chemical properties)
Ununseptium (unknown chemical properties)
Ununoctium (unknown chemical properties)
Bi

Uup

(Uhe)
fleroviumununpentiumlivermorium
Atomic number 115
Standard atomic weight [289]
Element category unknown, but probably a post-transition metal
Group, period, block group 15 (pnictogens), period 7, p-block
Electron configuration [Rn] 5f14 6d10 7s2 7p3 (predicted)[1]
per shell: 2, 8, 18, 32, 32, 18, 5 (predicted)
Physical properties
Phase solid (predicted)[1]
Melting point 670 K ​(400 °C, ​750 °F) (predicted)[1][2]
Boiling point ~1400 K ​(~1100 °C, ​~2000 °F) (predicted)[1]
Density (near r.t.) 13.5 g·cm−3 (predicted)[2] (at 0 °C, 101.325 kPa)
Heat of fusion 5.90–5.98 kJ·mol−1 (extrapolated)[3]
Heat of vaporization 138 kJ·mol−1 (predicted)[2]
Atomic properties
Oxidation states 1, 3(prediction)[1][2]
Ionization energies 1st: 538.4 kJ·mol−1 (predicted)[1]
2nd: 1756.0 kJ·mol−1 (predicted)[2]
3rd: 2653.3 kJ·mol−1 (predicted)[2]
(more)
Atomic radius empirical: 187 pm (predicted)[1][2]
Covalent radius 156–158 pm (extrapolated)[3]
Miscellanea
CAS Number 54085-64-2
History
Naming IUPAC systematic element name
Discovery Joint Institute for Nuclear Research and Lawrence Livermore National Laboratory (2003)
Most stable isotopes
Main article: Isotopes of ununpentium
iso NA half-life DM DE (MeV) DP
290Uup syn 16 ms[4] α 9.95 286Uut
289Uup syn 220 ms[4] α 10.31 285Uut
288Uup syn 87 ms α 10.46 284Uut
287Uup syn 32 ms α 10.59 283Uut
· references

Ununpentium is the temporary name of a synthetic superheavy element in the periodic table that has the temporary symbol Uup and has the atomic number 115. It is an extremely radioactive element; its most stable known isotope, ununpentium-289, has a half-life of only 220 milliseconds.[4] It is also known as eka-bismuth or simply element 115. Ununpentium was first created in 2003 by the Joint Institute for Nuclear Research in Dubna, Russia, although this discovery is still awaiting confirmation by IUPAC. About 50 atoms of ununpentium have been observed to date, all of which have been shown to have mass numbers from 287 to 290.

In the periodic table, it is a p-block transactinide element. It is a member of the 7th period and is placed in group 15 as the heaviest pnictogen, although it has not been confirmed to behave as the heavier homologue to the pnictogen bismuth. Ununpentium is calculated to have some similar properties to its lighter homologues, nitrogen, phosphorus, arsenic, antimony, and bismuth, although it should also show several major differences from them.

History[edit]

Discovery[edit]

Simulation of an accelerated calcium-48 ion about to collide with an americium-243 target atom.

The first report of the synthesis of ununpentium came in August 2003 and was reported on February 2, 2004, in Physical Review C by a team composed of Russian scientists at the Joint Institute for Nuclear Research (JINR) in Dubna, and American scientists at the Lawrence Livermore National Laboratory. The team reported that they bombarded americium-243 with calcium-48 ions to produce four atoms of ununpentium. These atoms decayed by emission of alpha-particles to ununtrium in approximately 100 milliseconds.[5][6]

243
95
Am
+ 48
20
Ca
288
115
Uup
+ 3 1
0
n
284
113
Uut
+ α
243
95
Am
+ 48
20
Ca
287
115
Uup
+ 4 1
0
n
283
113
Uut
+ α

The Dubna–Livermore collaboration has strengthened their claim for the discoveries of ununpentium and ununtrium by conducting chemical experiments on the final decay product 268Db. This was valuable as none of the nuclides in this decay chain were previously known, so that their claim was not supported by any previously obtained experimental data (as none existed), and chemical experimentation would strengthen the case for their claim. In June 2004 and again in December 2005, this dubnium isotope was successfully identified by extracting the final decay products, measuring spontaneous fission (SF) activities and using chemical identification techniques to confirm that they behave like a group 5 element (as dubnium is known to be in group 5 of the periodic table).[1][7] Both the half-life and decay mode were confirmed for the proposed 268Db which lends support to the assignment of the parent nucleus to ununpentium.[7][8] Further experiments at Dubna in 2005 have fully confirmed the decay data for ununpentium and its immediate daughter ununtrium, but in 2011, the IUPAC/IUPAP Joint Working Party (JWP) did not recognize the two elements as having been discovered because current theory could not distinguish between group 4 and group 5 elements by their chemical properties with sufficient confidence, but the identification of the daughter dubnium isotope was the most important factor in confirming the discovery of ununpentium and ununtrium.[9] Furthermore, the decay properties of all the nuclei in the decay chain of ununpentium had not been previously characterized before the Dubna experiments, a situation which the JWP generally considers "troublesome, but not necessarily exclusive".[9]

Naming[edit]

Ununpentium is the second-lightest element that has not yet received an official name. Using Mendeleev's nomenclature for unnamed and undiscovered elements, ununpentium is sometimes known as eka-bismuth. In 1979 IUPAC recommended that the placeholder systematic element name ununpentium (with the corresponding symbol of Uup)[10] be used until the discovery of the element is confirmed and a name is decided on. These recommendations are largely ignored among scientists, who call it "element 115", with the symbol of (115) or even simply 115.[1]

Road to confirmation[edit]

Two heavier isotopes of ununpentium, 289Uup and 290Uup, were discovered in 2009–2010 as daughters of the ununseptium isotopes 293Uus and 294Uus.[11] The JINR also has future plans to study lighter isotopes of element 115 by replacing the americium-243 target with the lighter isotope americium-241.[12]

The IUPAC/IUPAP Joint Working Party (JWP) will decide which team officially discovered ununpentium and give that team the right to suggest a permanent name for it. In 2011, it evaluated the 2004 and 2007 Dubna experiments, and concluded that they did not meet the criteria for discovery. Another evaluation of more recent experiments will take place within the next few years, and a claim to the discovery of ununpentium has been again put forward by Dubna.[9] In August 2013, a team of researchers at Lund University announced they had repeated the 2004 experiment, confirming Dubna's findings.[13][14] Researchers at the Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, Germany reported another successful confirmation just two weeks later, on September 10, 2013.[15] These confirmations considerably enhances the chances for IUPAC to officially recognize Dubna's claim to have discovered ununpentium.[9]

Predicted properties[edit]

Nuclear stability and isotopes[edit]

The expected location of the island of stability. The dotted line is the line of beta stability.

Ununpentium is expected to be in the middle of an island of stability centered around copernicium (element 112) and flerovium (element 114): the reasons for the presence of this island are however still not well understood.[16][17] Due to the expected high fission barriers, any nucleus within this island of stability exclusively decays by alpha decay and perhaps some electron capture and beta decay.[2] While the known isotopes of ununpentium do not actually have enough neutrons to be on the island of stability, they can be seen to approach the island as in general, the heavier isotopes are the longer-lived ones.[7][11]

The isotope 291Uup is especially interesting as it has only one neutron more than the heaviest known ununpentium isotope, 290Uup. It could plausibly be synthesized as the daughter of ununseptium-295, which in turn could be made from the reaction 249Bk(48Ca,2n)295Uus.[16] Calculations show that it may have a significant electron capture or positron emission decay mode in addition to alpha decaying and also have a relatively long half-life of several seconds. This would produce 291Fl, 291Uut, and finally 291Cn which is expected to be in the middle of the island of stability and have a half-life of about 1200 years, affording the most likely hope of reaching the middle of the island using current technology. Possible drawbacks are that the cross section of the production reaction of 295Uus is expected to be low and the decay properties of superheavy nuclei this close to the line of beta stability are largely unexplored.[16]

Other possibilities to synthesize nuclei on the island of stability include quasifission (partial fusion followed by fission) of a massive nucleus.[18] Such nuclei tend to fission, expelling doubly-magic or nearly doubly-magic fragments such as calcium-40, tin-132, lead-208, or bismuth-209.[19] Recently it has been shown that the multi-nucleon transfer reactions in collisions of actinide nuclei (such as uranium and curium) might be used to synthesize the neutron-rich superheavy nuclei located at the island of stability,[18] although formation of the lighter elements nobelium or seaborgium is more favored.[16] One last possibility to synthesize isotopes near the island is to use controlled nuclear explosions to create a neutron flux high enough to bypass the gaps of instability at 258–260Fm and at mass number 275 (atomic numbers 104 to 108), mimicking the r-process in which the actinides were first produced in nature and the gap of instability around radon bypassed.[16] Some such isotopes (especially 291Cn and 293Cn) may even have been synthesized in nature, but would have decayed away far too quickly (with half-lives of only thousands of years) and be produced in far too small quantities (about 10−12 the abundance of lead) to be detectable as primordial nuclides today outside cosmic rays.[16]

Physical and atomic[edit]

In the periodic table, ununpentium is a member of group 15, the pnictogens, below nitrogen, phosphorus, arsenic, antimony, and bismuth. Every previous pnictogen has five electrons in its valence shell, forming a valence electron configuration of ns2np3. In ununpentium's case, the trend should be continued and the valence electron configuration is predicted to be 7s27p3;[1] therefore, ununpentium will behave similarly to its lighter congeners in many respects. However, notable differences are likely to arise; a largely contributing effect is the spin–orbit (SO) interaction—the mutual interaction between the electrons' motion and spin. It is especially strong for the superheavy elements, because their electrons move much faster than in lighter atoms, at velocities comparable to the speed of light.[20] In relation to ununpentium atoms, it lowers the 7s and the 7p electron energy levels (stabilizing the corresponding electrons), but two of the 7p electron energy levels are stabilized more than the other four.[21] The stabilization of the 7s electrons is called the inert pair effect, and the effect "tearing" the 7p subshell into the more stabilized and the less stabilized parts is called subshell splitting. Computation chemists see the split as a change of the second (azimuthal) quantum number l from 1 to 12 and 32 for the more stabilized and less stabilized parts of the 7p subshell, respectively.[20][a] For many theoretical purposes, the valence electron configuration may be represented to reflect the 7p subshell split as 7s2
7p2
1/2
7p1
3/2
.[1] These effects cause ununpentium's chemistry to be somewhat different from that of its lighter congeners.

The valence electrons of ununpentium fall into three subshells: 7s (two electrons), 7p1/2 (two electrons), and 7p3/2 (one electron). The first two of these are relativistically stabilized and hence behave as inert pairs, while the last is relativistically destabilized and can easily participate in chemistry.[1] (The 6d electrons are not destabilized enough to participate chemically, although this may still be possible in the two previous elements ununtrium and flerovium.)[2] Thus, the +1 oxidation state should be favored, like Tl+, and consistent with this the first ionization potential of ununpentium should be around 5.58 eV, continuing the trend towards lower ionization potentials down the pnictogens.[1] Due to ununpentium and ununtrium both having one electron outside a quasi-closed shell configuration that can be delocalized in the metallic state, they should have similar melting and boiling points (both melting around 400 °C and boiling around 1100 °C) due to the strength of their metallic bonds being similar.[2] Additionally, the predicted ionization potential, ionic radius (1.5 Å for Uup+; 1.0 Å for Uup3+), and polarizability of Uup+ are expected to be more similar to Tl+ than its true congener Bi3+.[2] Ununpentium should be a dense metal due to its high atomic weight, with a density around 13.5 g/cm3.[2] The electron of the hydrogen-like ununpentium atom (oxidized so that it only has one electron, Uup114+) is expected to move so fast that it has a mass 1.82 times that of a stationary electron, due to relativistic effects. For comparison, the figures for hydrogen-like bismuth and antimony are expected to be 1.25 and 1.077 respectively.[20]

Chemical[edit]

Ununpentium is projected to be the third member of the 7p series of chemical elements and the heaviest member of group 15 (VA) in the Periodic Table, below bismuth. In this group, each member is known to portray the group oxidation state of +5 but with differing stability. For nitrogen, the +5 state is mostly a formal explanation of molecules like N2O5: it is very difficult to have five covalent bonds to nitrogen due to the lack of low-lying d-orbitals and the inability of the small nitrogen atom to accommodate five ligands. The +5 state is well represented for the essentially non-relativistic typical pnictogens phosphorus, arsenic, and antimony. However, for bismuth it becomes rare due to the relativistic stabilization of the 6s orbitals known as the inert pair effect, so that the 6s electrons are reluctant to bond chemically. It is expected that ununpentium will have an inert pair effect for both the 7s and the 7p1/2 electrons, as the binding energy of the lone 7p3/2 electron is noticeably lower than that of the 7p1/2 electrons. Nitrogen(I) and bismuth(I) are known but rare and ununpentium(I) is likely to show some unique properties,[22] probably behaving more like thallium(I) than bismuth(I).[2] Because of spin-orbit coupling, flerovium may display closed-shell or noble gas-like properties; if this is the case, ununpentium will likely be typically monovalent as a result, since the cation Uup+ will have the same electron configuration as flerovium, perhaps giving ununpentium some alkali metal character.[2] However, the Uup3+ cation would behave like its true lighter homolog Bi3+.[2] The 7s electrons are too stabilized to be able to contribute chemically and hence the +5 state should be impossible and ununpentium may be considered to have only three valence electrons.[2] Ununpentium would be quite a reactive metal, with an oxidation potential of about 1.5 V.[2]

The chemistry of ununpentium in aqueous solution should essentially be that of the Uup+ and Uup3+ ions. The former should be easily hydrolyzed and not be easily complexed with halides, cyanide, and ammonia.[2] Ununpentium(I) hydroxide (UupOH), carbonate (Uup2CO3), oxalate (Uup2C2O4), and fluoride (UupF) should be soluble in water; the sulfide (Uup2S) should be insoluble; and the chloride (UupCl), bromide (UupBr), iodide (UupI), and thiocyanate (UupSCN) should be only slightly soluble, so that adding excess hydrochloric acid would not noticeably affect the solubility of ununpentium(I) chloride.[2] Uup3+ should be about as stable as Tl3+ and hence should also be an important part of ununpentium chemistry, although its closest homolog among the elements should be its lighter congener Bi3+.[2] Ununpentium(III) fluoride (UupF3) and thiozonide (UupS3) should be insoluble in water, similar to the corresponding bismuth compounds, while ununpentium(III) chloride (UupCl3), bromide (UupBr3), and iodide (UupI3) should be readily soluble and easily hydrolyzed to form oxyhalides such as UupOCl and UupOBr, again analogous to bismuth.[2] Both ununpentium(I) and ununpentium(III) should be common oxidation states and their relative stability should depend greatly on what they are complexed with and the likelihood of hydrolysis.[2]

Experimental chemistry[edit]

Unambiguous determination of the chemical characteristics of ununpentium has yet to have been established.[23][24] In 2011, experiments were conducted to create ununtrium, flerovium, and ununpentium isotopes in the reactions between calcium-48 projectiles and targets of americium-243 and plutonium-244. However, the targets included lead and bismuth impurities and hence some isotopes of bismuth and polonium were generated in nucleon transfer reactions. This, while an unforeseen complication, could give information that would help in the future chemical investigation of the heavier homologs of bismuth and polonium, which are respectively ununpentium and livermorium.[24] The produced nuclides bismuth-213 and polonium-212m were transported as the hydrides 213BiH3 and 212mPoH2 at 850 °C through a quartz wool filter unit held with tantalum, showing that these hydrides were surprisingly thermally stable, although their heavier congeners UupH3 and LvH2 would be expected to be less thermally stable from simple extrapolation of periodic trends in the p-block.[24] Further calculations on the stability and electronic structure of BiH3, UupH3, PoH2, and LvH2 are needed before chemical investigations take place. However, ununpentium and livermorium are expected to be volatile enough as pure elements for them to be chemically investigated in the near future. The chief barrier to their chemical investigation at present is the lack of known isotopes of these elements which are long-lived enough.[24]

Notes[edit]

  1. ^ The quantum number corresponds to the letter in the electron orbital name: 0 to s, 1 to p, 2 to d, etc. See azimuthal quantum number for more information.

References[edit]

  1. ^ a b c d e f g h i j k l m Haire, Richard G. (2006). "Transactinides and the future elements". In Morss; Edelstein, Norman M.; Fuger, Jean. The Chemistry of the Actinide and Transactinide Elements (3rd ed.). Dordrecht, The Netherlands: Springer Science+Business Media. ISBN 1-4020-3555-1. 
  2. ^ a b c d e f g h i j k l m n o p q r s t u v Fricke, Burkhard (1975). "Superheavy elements: a prediction of their chemical and physical properties". Recent Impact of Physics on Inorganic Chemistry 21: 89–144. doi:10.1007/BFb0116498. Retrieved 4 October 2013. 
  3. ^ a b Bonchev, Danail; Kamenska, Verginia (1981). "Predicting the Properties of the 113–120 Transactinide Elements". J. Phys. Chem. 85: 1177–1186. doi:10.1021/j150609a021. 
  4. ^ a b c Oganessian, Y. T.; Abdullin, F. S.; Bailey, P. D. et al. (2010). "Synthesis of a New Element with Atomic Number Z=117". Physical Review Letters 104 (14): 142502. Bibcode:2010PhRvL.104n2502O. doi:10.1103/PhysRevLett.104.142502. PMID 20481935.  edit
  5. ^ Oganessian, Yu. Ts.; Utyonkoy, V. K.; Lobanov, Yu. V. et al. (2004). "Experiments on the synthesis of element 115 in the reaction 243Am(48Ca,xn)291−x115". Physical Review C 69 (2): 021601. Bibcode:2004PhRvC..69b1601O. doi:10.1103/PhysRevC.69.021601. 
  6. ^ Oganessian et al. (2003). "Experiments on the synthesis of element 115 in the reaction 243Am(48Ca,xn)291−x115". JINR preprints. 
  7. ^ a b c "Results of the experiment on chemical identification of Db as a decay product of element 115", Oganessian et al., JINR preprints, 2004. Retrieved on 3 March 2008
  8. ^ Oganessian, Yu. Ts.; Utyonkov, V.; Dmitriev, S.; Lobanov, Yu.; Itkis, M.; Polyakov, A.; Tsyganov, Yu.; Mezentsev, A.; Yeremin, A.; Voinov, A. A. et al. (2005). "Synthesis of elements 115 and 113 in the reaction 243Am + 48Ca". Physical Review C 72 (3): 034611. Bibcode:2005PhRvC..72c4611O. doi:10.1103/PhysRevC.72.034611. 
  9. ^ a b c d Barber, Robert C.; Karol, Paul J; Nakahara, Hiromichi; Vardaci, Emanuele; Vogt, Erich W. (2011). "Discovery of the elements with atomic numbers greater than or equal to 113 (IUPAC Technical Report)". Pure Appl. Chem. 83 (7): 1485. doi:10.1351/PAC-REP-10-05-01. 
  10. ^ Chatt, J. (1979). "Recommendations for the Naming of Elements of Atomic Numbers Greater than 100". Pure Appl. Chem. 51 (2): 381–384. doi:10.1351/pac197951020381. 
  11. ^ a b Oganessian, Y. T.; Abdullin, F. S.; Bailey, P. D. et al. (2010). "Synthesis of a New Element with Atomic Number Z=117". Physical Review Letters 104 (14): 142502. Bibcode:2010PhRvL.104n2502O. doi:10.1103/PhysRevLett.104.142502. PMID 20481935.  edit
  12. ^ "Study of heavy and superheavy nuclei (see experiment 1.5)". Flerov Laboratory of Nuclear Reactions. 
  13. ^ "EXISTENCE OF NEW ELEMENT CONFIRMED". Lund University. 27 August 2013. Retrieved 27 August 2013. 
  14. ^ "Spectroscopy of element 115 decay chains (Accepted for publication on Physical Review Letters on 9 August 2013)". Retrieved 2 September 2013. 
  15. ^ "Phys. Rev. Lett. 111, 112502 (2013): Spectroscopy of Element 115 Decay Chains". Prl.aps.org. Retrieved 2013-09-28. 
  16. ^ a b c d e f Zagrebaev, Valeriy; Karpov, Alexander; Greiner, Walter (2013). "Future of superheavy element research: Which nuclei could be synthesized within the next few years?". Journal of Physics: Conference Series 420. IOP Science. pp. 1–15. Retrieved 20 August 2013. 
  17. ^ Considine, Glenn D.; Kulik, Peter H. (2002). Van Nostrand's scientific encyclopedia (9 ed.). Wiley-Interscience. ISBN 978-0-471-33230-5. OCLC 223349096. 
  18. ^ a b Zagrebaev, V.; Greiner, W. (2008). "Synthesis of superheavy nuclei: A search for new production reactions". Physical Review C 78 (3): 034610. arXiv:0807.2537. Bibcode:2008PhRvC..78c4610Z. doi:10.1103/PhysRevC.78.034610. 
  19. ^ "JINR Annual Reports 2000–2006". JINR. Retrieved 2013-08-27. 
  20. ^ a b c Thayer, John S. (2010). Chemistry of Heavier Main Group Elements. pp. 63–67, 83. doi:10.1007/9781402099755_2. 
  21. ^ Faegri, K.; Saue, T. (2001). "Diatomic molecules between very heavy elements of group 13 and group 17: A study of relativistic effects on bonding". Journal of Chemical Physics 115 (6): 2456. Bibcode:2001JChPh.115.2456F. doi:10.1063/1.1385366. 
  22. ^ Keller, O. L., Jr.; C. W. Nestor, Jr. (1974). "Predicted properties of the superheavy elements. III. Element 115, Eka-bismuth". Journal of Physical Chemistry 78 (19): 1945. doi:10.1021/j100612a015. 
  23. ^ Düllmann, Christoph E. (2012). "Superheavy elements at GSI: a broad research program with element 114 in the focus of physics and chemistry". Radiochimica Acta 100 (2): 67–74. doi:10.1524/ract.2011.1842. 
  24. ^ a b c d Eichler, Robert (2013). "First foot prints of chemistry on the shore of the Island of Superheavy Elements". Journal of Physics: Conference Series (IOP Science) 420 (1). doi:10.1088/1742-6596/420/1/012003. Retrieved 11 September 2014. 

External links[edit]