Four elements added to the periodic table

Four new chemical elements will take their places in the periodic table, the International Union of Pure and Applied Chemistry (IUPAC) announced last week. IUPAC verified the discoveries of elements 113, 115, 117, and 118, which complete the periodic table's seventh row.

Element 113 was discovered by a collaboration at RIKEN in Japan, and elements 115 and 117 were discovered by a collaboration between the Joint Institute for Nuclear Research in Dubna, Russia, Lawrence Livermore National Laboratory, and Oak Ridge National Laboratory. Element 118 was discovered by a collaboration between the Joint Institute for Nuclear Research and Lawrence Livermore. The collaborations will be given naming rights for the new elements.

The following papers published in APS journals helped clinch the case for discovery of the various elements:

Element 115:
PRC: Experiments on the synthesis of element 115 in the reaction²⁴³Am(⁴⁸Ca,xn)^291−x115

PRL: Spectroscopy of Element 115 Decay Chains
Physics Synopsis: Element 115 Confirmed

Element 117:
PRL: Synthesis of a New Element with Atomic Number Z=117
Physics Viewpoint: Exploring the island of superheavy elements

PRL: ⁴⁸Ca+²⁴⁹Bk Fusion Reaction Leading to Element Z=117: Long-Lived α-Decaying ²⁷⁰Db and Discovery of ²⁶⁶Lr
Physics Synopsis: Element Z=117 Confirmed

Element 118:
PRC: Synthesis of the isotopes of elements 118 and 116 in the ²⁴⁹Cf and ²⁴⁵Cm+⁴⁸Ca fusion reactions