Copies of the periodic table are found on the walls of laboratories and classrooms around the world, so when an element is added to this iconic fixture, it becomes a global story. This past December it got even better: four spaces were filled in, completing the table’s seventh period.

“There are chemists dancing up and down, dotting i’s and crossing t’s,” says Bryan Henry, former president of the International Union of Pure and Applied Chemistry (IUPAC) and professor emeritus in the Department of Chemistry at the University of Guelph in Ontario. Henry regards the discovery of these elements as impressive, not simply because they were being observed at intervals on the order of a femtosecond but also because they had to be observed indirectly. “We found out what these new elements are by what they decay into,” says Henry, a former chair of the Chemical Institute of Canada. 

Not surprisingly, a great deal of collaboration went into each discovery of these elements. Atomic number 113 was found by a group at the RIKEN Nishina Center for Accelerator-based Science in Japan, while the identification of atomic number 115, 117 and 118 represented almost a decade’s worth of collaboration between researchers at Russian’s Joint Institute for Nuclear Research, Lawrence Livermore National Laboratory in California and Oak Ridge National Laboratory in Tennessee.
Deciding a new element has been confirmed is among the most prominent roles of IUPAC, which shares responsibility for the periodic table with the International Union of Pure and Applied Physics (IUPAP). Both organizations are the better part of a century old and over the last 40 years the IUPAC/IUPAP Joint Working Party has ushered in more than two dozen new elements. “The elements that are being filled in on the periodic table now are all radioactive and have very short half-lives,” says Edmonton’s King’s University College chemistry professor Peter Mahaffy, a past chair of IUPAC’s Committee on Chemistry Education. “Competing research groups will sometimes each lay claim to the discovery and so very careful work is required to show that results are reproducible and to establish who should be credited with it,” Mahaffy says. 

The IUPAC/IUPAP Joint Working Party published technical reports on the new elements in Pure and Applied Chemistry early this year. The rest of the world will then have a chance to review the findings and comment on names and symbols proposed by members of the various research groups. By the end of the year, it will be time for those periodic table posters hanging on walls to be replaced by one that includes these four newcomers.