There are two new additions in periodic table of elements. The discovery of the elements with atomic number 114 and 116 has been agreed by International Union of Pure and Applied Chemistry (IUPAC) according to standard criterion. These two man-made elements with atomic numbers 114 and 116 have their provision number based names ununquadium and ununhexium, respectively until these are assigned acceptable names.
These two elements have been discovered by a Russia-USA collaborative work between scientists from the Joint Institute for Nuclear Research in Dubna, Russia and from Lawrence Livemore, California, USA (the Dubna-Livermore collaborations).
IUPAC has confirmed the recognition of the element in a letter to the leaders of project and invited the collaborating scientists, from the Joint Institute for Nuclear Research in Dubna, Russia, and Lawrence Livermore National Laboratory in California, to propose names for the new elements. The suggested names go through a review process before adoption by the IUPAC Council.
Both the newly discovered elements have higher atomic numbers than any element of periodic table that has been recognized by IUPAC. All elements with atomic numbers above 92 decay relatively quickly and are mostly man-made, although elements 93 and 94 (neptunium and plutonium) do exist naturally in trace quantities.
In a news released by IUPAC1 states “The IUPAC/IUPAP Joint Working Party (JWP) on the priority of claims to the discovery of new elements has reviewed the relevant literature pertaining to several claims. In accordance with the criteria for the discovery of elements previously established by the 1992 IUPAC/IUPAP Transfermium Working Group, and reiterated by the 1999 and 2003 IUPAC/IUPAP JWPs, it was concluded that “the establishment of the identity of the isotope 283Cn by a large number of decaying chains, originating from a variety of production pathways essentially triangulating its A,Z character enables that nuclide’s use in unequivocally recognizing higher-Z isotopes that are observed to decay through it.” From 2004 Dubna-Livermore collaborations the JWP notes: (i) the internal redundancy and extended decay chain sequence for identification of Z = 287114 from 48Ca + 242Pu fusion (Oganessian et al. Eur. Phys. J. A 19, 3 (2004) and Phys. Rev. C 70, 064609 (2004)); and (ii) that the report of the production of 291116 from the fusion of 48Ca with 245Cm is supported by extended decay chains that include, again, 283Cn and descendants (Oganessian et al. Phys. Rev. C 69, 054607 (2004)). It recommends that the Dubna-Livermore collaborations be credited with discovery of these two new elements.”
The technical report synopsis2 of the relevant experiments and related efforts has been published in a technical report published online in Pure and Applied Chemistry on 1 June 2011.
Also the IUPAC stated that ‘Review of the claims associated with elements 113, 115, and 118 are at this time not conclusive and evidences have not met the criteria for discovery’. These new elements with atomic number 114 and 116 fill excitment among physicists and chemists while world is celebrating the International Year of Chemistry.