Ununoctium: the essentials

Experiments conducted at Dubna in Russia at the Flerov Laboratory of Nuclear Reactions (by workers from the Joint Institute for Nuclear Research in Russia and the Lawrence Livermore National Laboratory in the USA) indicate that element 118 (ununoctium, Uuo) was produced. Not too much though, one atom in the spring of 2002 and two more in 2005.

Ununoctium: historical information

Ununoctium was discovered by (not yet confirmed) in 2002 (not yet confirmed. A claim in 1999 was retracted later) at (not yet confirmed). Origin of name: temporary systematic IUPAC nomenclature.

Experiments conducted at Dubna in Russia at the Flerov Laboratory of Nuclear Reactions (by workers from the Joint Institute for Nuclear Research in Russia and the Lawrence Livermore National Laboratory in the USA) indicate that element 118 (ununoctium, Uuo) was produced. Not too much though, one atom in the spring of 2002 and two more in 2005.

The 2002 experiment involved firing a beam of 4820Ca at 24998Cf. The experiment took 4 months and involved a beam of 2.5 x 1019 calcium ions to produce the single event believed to be the synthesis of element 118 (ununoctium) as the 249118Uuo isotope. Three neutrons are released during this process

24998Cf + 4820Ca → 294118Uuo + 31n

This research was reported at an IUPAC conference in China (Yu. Ts. Oganessian, "Synthesis and decay properties of superheavy elements", Pure Appl. Chem., 2006, 78, 889-904.) in August 2006 and then more recently in Phys Rev C [Yu. Ts. Oganessian, V. K. Utyonkov, Yu. V. Lobanov, F. Sh. Abdullin, A. N. Polyakov, R. N. Sagaidak, I. V. Shirokovsky, Yu. S. Tsyganov, A. A. Voinov, G. G. Gulbekian, S. L. Bogomolov, B. N. Gikal, A. N. Mezentsev, S. Iliev, V. G. Subbotin, A. M. Sukhov, K. Subotic, V. I. Zagrebaev, G. K. Vostokin, M. G. Itkis, K. J. Moody, J. B. Patin, D. A. Shaughnessy, M. A. Stoyer, N. J. Stoyer, P. A. Wilk, J. M. Kenneally, J. H. Landrum, J. F. Wild, and R. W. Lougheed, "Synthesis of the isotopes of elements 118 and 116 in the 249Cf and 245Cm+48Ca fusion reactions", Phys. Rev. C, 2006, 74, 044602].

Earlier, a team of Berkeley Lab scientists announced in 1999 the observation of what appeared to be element 118 but retracted the claim after several confirmation experiments failed to reproduce the results. Please see this page for more details. In this work it was claimed that elements 118 and 116 were formed by accelerating a beam of krypton-86 (8636Kr) ions to an energy of 449 million electron volts and directing the beam onto targets of lead-208 (20882Pb). After 11 days work, just three atoms of the new element were identified. The production rates for element 118 are approximately one in every 1012 interactions.

20882Pb + 8636Kr → 293118Uuo + 1n

These experiments were carried out following calculations by Robert Smolanczuk (Soltan Institute for Nuclear Studies, Poland) on the fusion of atomic nucleii. His calculations suggested that it might be possible to make element 118 by fusing lead with krypton under carefully controlled conditions.

Ununoctium around us Read more »

Element 118 has no biological role since it does not occur in nature.

Element 118 (ununoctium, Uuq) does not occur at all in the geosphere. It would constitute a radiation hazard if enough was ever assembled in one place.

Abundances for cobalt in a number of different environments. More abundance data » »
Location ppb by weight ppb by atoms Links
Universe (no data) (no data) Abundance in the universe of the chemical elements displayed on a miniature periodic table
Crustal rocks (no data) (no data) Abundance in the earth's crust of the chemical elements displayed on a miniature periodic table
Human (no data) ppb by weight (no data) atoms relative to C = 1000000 Abundance in humans of the chemical elements displayed on a miniature periodic table

Physical properties Read more »

Crystal structure Read more »

The solid state structure of ununoctium is: .

Ununoctium: orbital properties Read more »

Ununoctium atoms have 118 electrons and the shell structure is 2.8.18.32.32.18.8. The ground state electronic configuration of neutral Ununoctium is [Rn].5f14.6d10.7s2.7p6 (a guess based upon that of radon) and the term symbol of Ununoctium is 1S0 (a guess based upon guessed electronic structure).

Isolation

Isolation:

Experiments conducted at Dubna in Russia at the Flerov Laboratory of Nuclear Reactions (by workers from the Joint Institute for Nuclear Research in Russia and the Lawrence Livermore National Laboratory in the USA) indicate that element 118 (ununoctium, Uuo) was produced. Not too much though, one atom in the spring of 2002 and two more in 2005.

The 2002 experiment involved firing a beam of 4820Ca at 24998Cf. The experiment took 4 months and involved a beam of 2.5 x 1019 calcium ions to produce the single event believed to be the synthesis of element 118 (ununoctium) as the 294118Uuo isotope. Three neutrons are released during this process.

24998Cf + 4820Ca → 294118Uuo + 31n

This ununoctium isotope then loses three alpha particles in rapid succesion:

294118Uuo → 290116Lv + 42He (1.29 milliseconds)

290116Lv → 286114Fl + 42He (14.4 milliseconds)

286114Fl → 282112Uub + 42He (230 milliseconds)

The 282112Cn species then undergoes spontaneous fission (denoted SF) to other species. An important part of this work was additional work synthesising isotopes of element 116 through irradiation of 245Cm (as opposed to 249Cm referred to above).

24598Cf + 4820Ca → 290116Lv + 31n

Analysis of this reaction very clearly indicates that 290116Lv is indeed a decomposition product of 294118Uuo. This research was reported at an IUPAC conference in China (Yu. Ts. Oganessian, "Synthesis and decay properties of superheavy elements", Pure Appl. Chem., 2006, 78, 889-904.) in August 2006 and then more recently in Phys Rev C [Yu. Ts. Oganessian, V. K. Utyonkov, Yu. V. Lobanov, F. Sh. Abdullin, A. N. Polyakov, R. N. Sagaidak, I. V. Shirokovsky, Yu. S. Tsyganov, A. A. Voinov, G. G. Gulbekian, S. L. Bogomolov, B. N. Gikal, A. N. Mezentsev, S. Iliev, V. G. Subbotin, A. M. Sukhov, K. Subotic, V. I. Zagrebaev, G. K. Vostokin, M. G. Itkis, K. J. Moody, J. B. Patin, D. A. Shaughnessy, M. A. Stoyer, N. J. Stoyer, P. A. Wilk, J. M. Kenneally, J. H. Landrum, J. F. Wild, and R. W. Lougheed, "Synthesis of the isotopes of elements 118 and 116 in the 249Cf and 245Cm+48Ca fusion reactions", Phys. Rev. C, 2006, 74, 044602].

Earlier, a team of Berkeley Lab scientists announced in 1999 the observation of what appeared to be element 118 but retracted the claim after several confirmation experiments failed to reproduce the results. This means that the following apparently is wrong. Please see this page for more details. In this work it was claimed that elements 118 and 116 were formed by accelerating a beam of krypton-86 (8636Kr) ions to an energy of 449 million electron volts and directing the beam onto targets of lead-208 (20882Pb). After 11 days work, just three atoms of the new element were identified. The production rates for element 118 are approximately one in every 1012 interactions.

20882Pb + 8636Kr → 293118Uuo + 1n

The element 118 nucleus was said to decay less than a millisecond after its formation by emitting an α-particle resulting in an isotope of element 116 (mass number 289, containing 116 protons and 173 neutrons). This isotope of element 116 undergoes further α-decay processes to an isotope of element 114 and so on down to at least element 106 (seaborgium).

293118Uuo → 289116Lv + 42He (0.12 milliseconds)

289116Lv → 285114Fl + 42He (0.60 milliseconds)

285114Fl → 281112Cn + 42He (0.58 milliseconds)

281112Cn → 277Ds + 42He (0.89 milliseconds)

277Ds → 273108Hs + 42He (3 milliseconds)

273108Hs → 269106Sg + 42He (1200 milliseconds)

Ununoctium isotopes Read more »

Table. Stables isotopes of cobalt.
Isotope Mass / Da Natural
abundance
(atom %)
Nuclear
spin (I)
Nuclear
magnetic
moment (μ/μN)
nil

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