Ununoctio One Hundred eighteenth element of the Periodic Table
Year - 1999
Ununocyte (from Latin one, one, eight) is the provisional name of the atomic number 118 synthetic overweight chemical element (118 protons and 118 electrons). Its temporary chemical symbol is Uuo. It occupies group 18 (VIIIA or 0) of the periodic table together with the noble gases.
Key Features:
From the position in the periodic table, the forecast is that it presents similar chemical properties to radon. Therefore it is also known by the name of eka-radon. It will probably be the second radioactive gas element, and the first gas with semiconductivity. However, data from calculations suggest that the element may not be gaseous, as this is unlikely for an element with such a high mass due to increased intermolecular interactions. This fact is further reinforced by the influence of relativistic quantum effects.
The melting point of the element is estimated to be around 47 ° C (320K) so that it is a solid at room temperature. It is also assumed, based on the tendency observed in the group, that the boiling point of the element is only about 2 ° C above the melting point. In addition, it is predicted that it will be far more reactive than the rest of the group, even more reactive than Flerovium and the Copernicium, due to the relativistic destabilization of 7s and 7p orbitals in the full valence layer of period 7.
History:
In 1999, researchers at Lawrence Berkeley National Laboratory published the discovery of elements 116 and 118 in an article in the Physical Review Letters. A year later they published a retraction, after other researchers were unable to duplicate the results. In June 2002, the laboratory director announced that the original claim for the discovery of these two elements had been based on data produced by the report's lead author, Victor Ninov.
On October 10, 2006, researchers from the Russian Joint Institute for Nuclear Research and the US Lawrence Livermore National Laboratory announced in Physical Review C that they had indirectly detected element 118 produced by collisions of californium and calcium atoms. The researchers observed the decay of three atoms, not the atoms themselves.
A half-life of 0.89 ms was observed. Element 118 decays element 116 by alpha decay. Within seconds, the subsequent alpha decay proceeds until it reaches the more stable seaborgium-271 with a half-life of 2.4 min. This will lead the alpha decay to ruterphoron-267 with a half-life of 1.3 h. "Ununoctio" is a systematic, temporary name adopted by IUPAC for element 118.
Year - 2016 (WIKIPEDIA)
Oganesson is a synthetic chemical element with the symbol Og and atomic number 118. It was first synthesized in 2002 at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia, by a joint team of Russian and American scientists. In December 2015, it was recognized as one of four new members by the Joint Working Group of the international scientific bodies IUPAC and IUPAP. It was formally named on November 28, 2016. [15] [16] The name is in keeping with the tradition of honoring a scientist, in this case nuclear physicist Yuri Oganessian, who played a leading role in the discovery of the heavier elements. Of the periodic table.