The periodic table gets four new chemical elements – 113, 115, 117 and 118 – so the seventh row in the scheme is now complete. The periodic table lists all the elements we know of – the tabular arrangement is set up according to the number of protons in their nucleus (atomic number), electron configurations, and recurring chemical properties.
The new additions are the first to be included in the table since 2011, when 114 and 116 were added to the list.
According to the Chemical Society, the first true iteration of the periodic table was produced by the Russian chemist and inventor Dmitri Ivanovich Mendeleev (1834-1907).
The four new elements – 113, 115, 117 & 118 – are in the dark blue squares above. (Image: iupac.org)
The International Union of Pure and Applied Chemistry (IUPAC), which decides whether to add new elements to the Periodic Table, said its Joint Working Party has verified the four candidate elements – 113, 115, 117 and 118 – and determined that the claims for their discoveries have been fulfilled.
7th row of Periodic Table complete
On 31st December, 2015, IUPAC said in a statement:
“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.”
IUPAC credited the following institutions for the discoveries:
Element 113: (temporary working name and symbol: ununtrium, Uut). The discovery was accredited to the RIKEN collaboration team in Japan.
“Element 113, discovered by a RIKEN group led by Kosuke Morita, has become the first element on the periodic table found in Asia. Rewarding nearly a decade of painstaking work by Morita’s group.”
Elements 115, 117, and 118: (temporary working names and symbols: ununpentium, Uup; ununseptium, Uus; and ununoctium, Uuo).
The collaboration between Oak Ridge National Laboratory, Oak Ridge, Tennessee; Lawrence Livermore National Laboratory, California; and the Joint Institute for Nuclear Research in Dubna, Russia has fulfilled the criteria for elements 115 and 117.
Illustration of element 117. (Image: Lawrence Livermore National Laboratory. Credit: Kwei-Yu Chu/LLNL)
The collaboration between the Lawrence Livermore National Laboratory in California, and the Joint Institute for Nuclear Research in Dubna, fulfilled the criteria for element 118.
Dawn Shaughnessy, Lawrence Livermore’s principle investigator for the Heavy Element Group, said:
“This is a very exciting time for our collaboration and shows that all of the hard work has paid off. It is especially gratifying to receive this news right as we enter a new year. I am so proud of all of the hard work that this group has done over the years performing these experiments. Our colleagues in Russia have worked endless hours at the accelerator working toward these results.”
“It is a wonderful gift to the entire group that we are recognized for our efforts in accomplishing these highly difficult experiments and for the years of work it takes to successfully create a new chemical element. Congratulations also to the team in Japan for their efforts in creating element 113. Those were extremely lengthy and difficult experiments and it is a credit to their program to be recognized in this way.”
Process for approving new names and symbols
IUPAC’s Inorganic Chemistry Division will check the proposed names and symbols for consistency, translatability into other languages, and possible previous historic usage in other cases.
IUPAC says a new element can be named after a place, country, mineral, mythological concept, property or scientist. After being accepted, the names and their two-letter symbols will be presented for public review for a period of five months, before the IUPAC Council makes the final decision.
Dr. Mark C. Cesa, IUPAC President, said:
“As the global organization that provides objective scientific expertise and develops the essential tools for the application and communication of chemical knowledge for the benefit of humankind, the International Union of Pure and Applied Chemistry is pleased and honored to make this announcement concerning elements 113, 115, 117, and 118 and the completion of the seventh row of the periodic table of the elements.”
“We are excited about these new elements, and we thank the dedicated scientists who discovered them for their painstaking work, as well the members of the IUPAC/IUPAP Joint Working Party for completing their essential and critically important task.”
Video – Brief history of the Periodic Table of Elements