Katrina Kramer reports that four new elements have just been added to the periodic table completing the 7th row of the table. But despite elements 113, 115 and 118 all being discovered in the early 2000s and 117 in 2010, there is still no sign of elements 119 and beyond. Why has no one created one of these new superheavyweights and when will chemists be able to start an eighth row on the periodic table? Since Edwin McMillan and Philip Abelson synthesized the first transuranium element neptunium in 1940, a steady stream of new elements has filled the lower rows of the periodic table. Each time a group claims to have synthesized a new element the International Union of Pure and Applied Chemistry (Iupac) must weigh the evidence presented.
Typically the claim of the first synthesis of a new superheavy element comes many years before enough evidence is gathered to get the nod of approval from Iupac. This is what makes the absence of any claim on the creation of element 119 or beyond surprising. But while no group has yet claimed to have created an element that belongs on the eighth row of the periodic table it is not from lack of trying. To create a new element, a heavy element target is bombarded with highly accelerated lighter element projectiles. As early as 2007, researchers at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia, and the Helmholtz Centre for Heavy Ion Research (GSI) in Darmstadt, Germany, tried to synthesise unbinilium or element 120 by bombarding plutonium with iron and uranium with nickel, respectively. However, both teams only observed an assortment of lighter nuclei and particles.
In order for scientists to be confident that they really have made a new element, they must follow the signature decay chains of the new element, explains James Roberto, associate laboratory director at Oak Ridge National Laboratory (ORNL) in the US.
Original working URL: https://www.chemistryworld.com/news/beyond-element-118-the-next-row-of-the-periodic-table/9400.article
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