Ununpentium

Ununpentium: the essentials

Experiments resulting in the formation of element 115 were reported in February 2004 following experiments carried out between 14 July - 10 August 2003 involving scientists at Dubna (Joint Institute for Nuclear Research at the U400 cyclotron with the Dubna gas-filled recoil separator, DGFRS) in Russia in a collaboration also involving scientists at the Lawrence Livermore National Laboratory, USA. Only four nuclei were identified and the claim has not yet been ratified, but the results are now published in a reputable peer-reviewed journal.

Ununpentium: historical information

Experimental results reported in 2004 involving the bomabardment of americium-243 with calcium-48 ions are consistent with the formation in the laboratory of a few atoms of elements 113 and 115. In experiments conducted at the JINR U400 cyclotron with the Dubna gas-filled separator between July 14 and Aug. 10, 2003, atomic decay patterns were observed said to confirm the existence of element 115 and element 113. In these decay chains, element 113 is produced via the α-decay of element 115.

The results are published in the 1 February 2004 issue of Physical Review C: "Experiments on the synthesis of element 115 in the reaction ²⁴³Am(⁴⁸Ca,xn)^291–x115", Yu. Ts. Oganessian, V. K. Utyonkoy, Yu. V. Lobanov, F. Sh. Abdullin, A. N. Polyakov, I. V. Shirokovsky, Yu. S. Tsyganov, G. G. Gulbekian, S. L. Bogomolov, A. N. Mezentsev, S. Iliev, V. G. Subbotin, A. M. Sukhov, A. A. Voinov, G. V. Buklanov, K. Subotic, V. I. Zagrebaev, M. G. Itkis, J. B. Patin, K. J. Moody, J. F. Wild, M. A. Stoyer, N. J. Stoyer, D. A. Shaughnessy, J. M. Kenneally, and R. W. Lougheed, Phys. Rev. C, 2004, 69, 021601(R).

Ununpentium: physical properties

• Melting point: no data K
• Boiling point: no data K
• Density of solid: 13000 (predicted) kg m^-3

 Read more » »

Ununpentium: orbital properties

• Ground state electron configuration:  [Rn].5f¹⁴.6d¹⁰.7s².7p³ (a guess based upon that of bismuth)
• Shell structure:  2.8.18.32.32.18.5
• Term symbol:   ⁴S_3/2 (a guess based upon guessed electronic structure)
• Pauling electronegativity: no data (Pauling units)
•  First ionisation energy: no data kJ mol^-1
•  Second ionisation energy: no data kJ mol^-1

 Read more » »

Isolation

Isolation: currently, the identification of element 115 is yet to be confirmed by IUPAC, but the experiments leading to element 115 are now published in a prestigious peer reviewed journal. As only about four atoms of element 115 have ever been made (through nuclear reactions involving fusing calcium nuclei with americium nuclei) isolation of an observable quantity has never been achieved, and may well never be.

²⁴³₉₅Am + ⁴⁸₂₀Ca → ²⁸⁷₁₁₅Uup + 4 ¹n

²⁴³₉₅Am + ⁴⁸₂₀Ca → ²⁸⁸₁₁₅Uup + 3 ¹n

In these first experiments, three nuclei of the ²⁸⁸Uup isotope were made and one of the ²⁸⁷Uup isotope. All the nuclei formed decayed in less than a second by emitting α-particles. These decays resulted in isotopes of element 113 (mass number 283 or 284, containing 113 protons and either 170 or 171 neutrons). These isotopes of element 113 are also radioactive and underwent further α-decay processes to isotopes of element 111 and so on down to at least element 105 (dubnium).

²⁸⁷₁₁₅Uup → ²⁸³₁₁₃Uut + ⁴₂He (46.6 milliseconds)

²⁸⁸₁₁₅Uup → ²⁸⁴₁₁₃Uut + ⁴₂He (80.3 milliseconds)

²⁸⁸₁₁₅Uup → ²⁸⁴₁₁₃Uut + ⁴₂He (18.6 milliseconds)

²⁸⁸₁₁₅Uup → ²⁸⁴₁₁₃Uut + ⁴₂He (280 milliseconds)

WebElements Shop

WebElements now has a WebElements shop at which you can buy periodic table posters, mugs, T-shirts, games, fridge magnets, molecular models, and more.

Buy our periodic table fridge magnets here