A team led by Yuri Oganessian of the Joint Institute for Nuclear Research in Dubna, Russia, reports smashing together calcium-48 — an isotope with 20 protons and 28 neutrons — with berkelium-249, which has 97 protons and 152 neutrons. The collision spit out neutrons to create two isotopes of an element with 117 protons, one with 176 neutrons and the other with 177.
The new element, which has yet to be named, slips into a place on the periodic table between elements 116 and 118, both of which have already been discovered. Such superheavy elements are usually very radioactive and decay away almost instantly. But many researchers think it is possible that even heavier elements may occupy an “island of stability” in which superheavy atoms stick around for a while.
The new work supports that view. Analyses of the radioactive decay of the new element, Oganessian’s team writes in the new paper, “represent an experimental verification for the existence of the predicted ‘Island of Stability’ for super-heavy elements.”