The scientific body in charge of chemistry’s periodic table has verified the discoveries of four elements – completing the seventh row of the century-old chart.
For now, the elements are known as ununtrium (Element 113), ununpentium (Element 115), ununseptium (Element 117) and ununoctium (Element 118). It’ll be up to the newly recognized discoverers to propose the officlal names. The numbers denote how many protons are in the element’s nucleus.
At least one of the elements was synthesized more than a decade ago, but it took years for the International Union of Pure and Applied Chemistry, or IUPAC, to confirm the evidence.
“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,” Paul Karol, a Carnegie Mellon University chemist who chairs the panel in charge of sorting out the discovery claims, said in IUPAC’s Dec. 30 announcement.
Credit for the discovery of Elements 115, 117 and 118 was given to collaborations involving scientists from the Joint Institute for Nuclear Research in Dubna, Russia, and from Lawrence Livermore National Laboratory and Oak Ridge National Laboratory.
The Dubna-Livermore collaboration also claimed discovery of Element 113, but IUPAC gave precedence instead to Japan’s RIKEN Institute, based on findings that were gathered between 2004 and 2012. This means Element 113 is the first chemical element discovered in Asia.
“Now that we have conclusively demonstrated the existence of Element 113, we plan to look to the uncharted territory of Element 119 and beyond, aiming to examine the chemical properties of the elements in the seventh and eighth rows of the periodic table, and someday to discover the island of stability,” RIKEN’s Kosuke Morita said in a news release.
The periodic table is arranged in rows and columns that group elements with similar chemical properties above and below each other. Element 119 (also known by its placeholder name, Ununennium) would be the first entry on the table’s eighth row. It’s expected to have the characteristics of an alkali metal.
The most recently discovered elements are highly unstable. Most of the synthesized atoms exist for only a fraction of a second before decaying into other elements. But physicists suspect that if they could get enough protons in the nucleus, they’d eventually create elements that reverse the trend and become more stable. That’s the “island of stability” that Morita referenced.