|Classification:||Ununseptium is a halogen (presumed)|
|Atomic weight:||(294), no stable isotopes|
|Neutrons in most abundant isotope:||177|
|Electron shells:||2, 8, 18, 32, 32, 18, 7|
|Electron configuration:||[Rn] 5f14 6d10 7s2 7p5 (presumed)|
|Specific heat capacity||–|
|Heat of fusion||–|
|Heat of atomization||–|
|Heat of vaporization||–|
|1st ionization energy||–|
|2nd ionization energy||–|
|3rd ionization energy||–|
|Minimum oxidation number||–|
|Min. common oxidation no.||–|
|Maximum oxidation number||–|
|Max. common oxidation no.||–|
|Electronegativity (Pauling Scale)||–|
|Reaction with air||–|
|Reaction with 15 M HNO3||–|
|Reaction with 6 M HCl||–|
|Reaction with 6 M NaOH||–|
|Ionic radius (1+ ion)||–|
|Ionic radius (2+ ion)||–|
|Ionic radius (3+ ion)||–|
|Ionic radius (1- ion)||–|
|Ionic radius (2- ion)||–|
|Ionic radius (3- ion)||–|
Discovery of Ununseptium
In 2009, the first atoms of element 117 were made in the Flerov Laboratory of Nuclear Reactions in Dubna, Russia. Evidence of the synthesis was published in April 2010, by scientific teams from Russia and the United States of America. (1), (2)
The research effort, led by Yuri Oganessian, was a collaboration between the Joint Institute of Nuclear Research (Dubna, Russia); the Research Institute for Advanced Reactors, Dimitrovgrad; Lawrence Livermore National Laboratory; Oak Ridge National Laboratory; Vanderbilt University, Tennessee; and the University of Nevada, Las Vegas.
The discovery has not yet been verified by IUPAC. Ununseptium’s place in the periodic table is unofficial until IUPAC validates its existence.
Calcium ions were formed into a beam in a cyclotron (a particle accelerator) and fired at a target layer of berkelium deposited 300 nm thick on titanium foil.
The first bombardment lasted 70 days. The berkelium was bombarded with over 7 trillion calcium-48 ions per second, accelerated to about 10% of the speed of light.
The data suggest five nuclei of interest were produced during the 70 day bombardment. As a consequence of the high energy of the impacts that created them, these nuclei instantly lost thermal energy by emitting four neutrons to form ununseptium-293.
The ununseptium-293 (approximate half-life 14 ms) decayed by alpha emission into element 115 (ununpentium). (2), (3)
In a second bombardment lasting 50 days, the speed of the bombarding calcium-48 ions was reduced. The resulting impacts were of lower energy and the single nucleus of interest that formed needed to emit just three neutrons to lose its excess energy, leading to the heavier ununseptium-294 isotope. The data suggest one atom of ununseptium-294 (approximate half-life 78 ms) was formed in the bombardment, decaying again to element 115.
As a result of its position in Group 17 of the periodic table, ununseptium is expected to have chemical properties characteristic of the halogens. The effects of relativistic electrons, however, may result in partial metalloid properties.
Jim Roberto from Oak Ridge said: “New isotopes observed in these experiments continue a trend toward higher lifetimes for increased neutron numbers, providing evidence for the proposed ‘island of stability’ for super-heavy nuclei.”
The joint teams at JINR in Dubna and Lawrence Livermore in California have published evidence for the synthesis of elements 113, 114, 115, 116, 117 and 118.
IUPAC has accepted the discoveries of element 114 (flerovium/ununquadium) and element 116 (livermorium/ununhexium). It has not yet considered the evidence for the discovery of element 117 (ununseptium).
Appearance and Characteristics
Ununseptium is harmful due to its radioactivity.
Ununseptium is a synthetic radioactive metal and has only been produced in minute amounts.
Uses of Ununseptium
Ununseptium is of research interest only.
Abundance and Isotopes
Abundance earth’s crust: nil
Abundance solar system: parts per trillion by weight, parts per trillion by moles
Cost, pure: $ per 100g
Cost, bulk: $ per 100g
Source: Data from the discovery teams suggest ununseptium may be produced by bombarding 249Bk with 48Ca in a heavy ion accelerator.
Isotopes: Initial data has identified 2 isotopes of ununseptium, with mass numbers 293 and 294. Neither are stable. Ununseptium-293’s approximate half-life is 14 ms and ununseptium-294’s is 78 ms.
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