The International Union of Pure and Applied Chemistry (IUPAC), which verifies claims of newly discovered elements, has announced that four new super-heavy elements have cleared the verification process and are now officially recognized.
The recognition of these four new elements completes the 7th row of the Periodic Table of the Elements, a table which most people studied in their high school chemistry class. Researchers consider the discovery and verification of new elements to be an honor greater than winning an Olympic gold medal, given that it is such a rare occurrence. In fact, researchers are already hard at work attempting to create elements in the lab that would begin an 8th row of the Periodic Table.
Teams from around the globe had created all four of these elements using particle accelerators to smash atoms together. None of them are stable elements, decaying into lighter particles almost instantly after their creation.
A press release from IUPAC provides the details of the announcement:
The fourth IUPAC/IUPAP Joint Working Party (JWP) on the priority of claims to the discovery of new elements has reviewed the relevant literature for elements 113, 115, 117, and 118 and has determined that the claims for discovery of these elements have been fulfilled, in accordance with the criteria for the discovery of elements of the IUPAP/IUPAC Transfermium Working Group (TWG) 1991 discovery criteria. These elements complete the 7th row of the periodic table of the elements, and the discoverers from Japan, Russia and the USA will now be invited to suggest permanent names and symbols. The new elements and assigned priorities of discovery are as follows:
Element 113 (temporary working name and symbol: ununtrium, Uut)
The RIKEN collaboration team in Japan have fulfilled the criteria for elementZ=113 and will be invited to propose a permanent name and symbol.
Elements 115, 117, and 118 (temporary working names and symbols: ununpentium, Uup; ununseptium, Uus; and ununoctium, Uuo)
The collaboration between the Joint Institute for Nuclear Research in Dubna, Russia; Lawrence Livermore National Laboratory, California, USA; and Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA have fulfilled the criteria for element Z=115, 117 and will be invited to propose permanent names and symbols.
The collaboration between the Joint Institute for Nuclear Research in Dubna, Russia and Lawrence Livermore National Laboratory, California, USA have fulfilled the criteria for element Z=118 and will be invited to propose a permanent name and symbol.
The priorities for four new chemical elements are being introduced simultaneously, after the careful verification of the discoveries and priorities. The decisions are detailed in two reports by the Joint Working Party (JWP), which includes experts drawn from IUPAC and IUPAP (the International Union of Pure and Applied Physics). These reports will be published in an early 2016 issue of the IUPAC journal Pure and Applied Chemistry (PAC).The JWP has reviewed the relevant literature pertaining to several claims of these new elements. The JWP has determined that the RIKEN collaboration have fulfilled the criteria for the discovery of element with atomic numbers Z=113. Several studies published from 2004 to 2012 have been construed as sufficient to ratify the discovery and priority.
In the same PAC report, the JWP also concluded that the collaborative work between scientists from the Joint Institute for Nuclear Research in Dubna, Russia; from Lawrence Livermore National Laboratory, California, USA; and from Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA (the Dubna-Livermore-Oak Ridge collaborations), starting in 2010, and subsequently confirmed in 2012 and 2013, have met the criteria for discovery of the elements with atomic numbersZ=115 and Z=117.
Finally, in a separate PAC article the Dubna–Livermore collaboration started in 2006 is reported as having satisfied the criteria for discovery of element Z=118.
“A particular difficulty in establishing these new elements is that they decay into hitherto unknown isotopes of slightly lighter elements that also need to be unequivocally identified” commented JWP chair Professor Paul J. Karol, “but in the future we hope to improve methods that can directly measure the atomic number, Z“.
“The chemistry community is eager to see its most cherished table finally being completed down to the seventh row. IUPAC has now initiated the process of formalizing names and symbols for these elements temporarily named as ununtrium, (Uut or element 113), ununpentium (Uup, element 115), ununseptium (Uus, element 117), and ununoctium (Uuo, element 118)” said Professor Jan Reedijk, President of the Inorganic Chemistry Division of IUPAC.
The discoverers now have the opportunity to propose permanent names that conform to IUPAC’s guidelines, so sometime later in 2016 the new official Periodic Table will be published with those newly named elements. See the press release on the IUPAC website for additional details.
Source: IUPAC.org – “Discovery and Assignment of Elements with Atomic Numbers 113, 115, 117 and 118“