What is the heaviest element that can exist in Nature? Slowly, but with persistence, nuclear physicists have pushed that question to extreme limits. The past few decades have seen a tremendous progress in experimental ingenuity and theoretical methodology to study and characterise heavier and heavier elements. The search culminated in 2016 when IUPAC and IUPAP acknowledged the discovery of element 118, oganesson, Og. With Og, currently the heaviest known element in the universe, the first seven periods of the Periodic Table of Elements is completed.

When claims for the discovery of a new element is being put forward it is the important task of IUPAP and IUPAC to validate them. In 2016, on the initiative by the Presidents of IUPAP and IUPAC, Bruce Mckellar and Natalia Tarasova, two important actions were being undertaken. First it was decided to overlook the whole validation procedure. To this end a document has been produced: ”IUPAC and IUPAP Procedures for Validating Claims for the Discovery of New Elements and Naming those Elements”. Secondly it was realised that the criteria and rules that are to be followed in the validation procedure also were in need of a revision. The old criteria were set down almost thirty years ago by the Transfermium Working Group, a group of scientists jointly appointed by the two unions. It was now decided to establish a new Joint Working Group, JWG, consisting of three members appointed  by IUPAP and three by IUPAC, to undertake that revision.

A first meeting of the JWG was held in May 2017. One year later the report was submitted to the Presidents of IUPAP and IUPAC. It has been provisionally accepted by both unions, and recently also accepted for publication in the journal of Pure and Applied Chemistry. It is open for comment for 5 months.

Comments should be directed to both Presidents, and will be accepted up to 31 March 2019:
Kennedy Reed, President of IUPAP
Zhou Qifeng, President of IUPAC

Full text published in Pure Appl. Chem. 2018; 90(11): 1773–1832; https://doi.org/10.1515/pac-2018-0918

Corresponding Author: Claes Fahlander, Chair of the C12 Commission