The Discovery of Element 112 - proposed name COPERNICIUM

Figure. 1: The element 112 was identified via this decay chain. All measured α-particle energies and the corresponding decay times are given. (Image source: GSI Helmholtzzentrum für Schwerionenforschung)

2004
Japanese researches at RIKEN (Institute of Physical and Chemical Research, Tokyo), confirm the discovery of ²⁷⁷112 with the same fusion reaction ⁷⁰Zn + ²⁰⁸Pb.

1998 – 2004
Further nuclei of element 112 with larger neutron numbers (^282-285112) have been produced at the Flerov Laboratory of Nuclear Research (JINR) in Dubna, Russia in the reaction ⁴⁸Ca + ²³⁸U (20 and 92 protons respectively).

2005 -2007
Four nuclei of ²⁸³112 have been produced at SHIP in the reaction ⁴⁸Ca + ²³⁸U.

19 May 2009
The International Union of Pure and Applied Chemistry (IUPAC) assigns the discovery of element 112 to Sigurd Hofmann and his group.
See IUPAC report here.

13 July 2009
The group of Sigurd Hofmann proposes to the IUPAC the name COPERNICIUM (symbol Cp) for element 112.

"With our suggestion we want to honour a scientist, an astronomer, who lived in the period of the transition from the middle ages to modern times. He was born on February 19th, 1473, in Torun, Poland, and died on May 24th, 1543, in Frombork/Frauenburg. His work was of exceptional influence on the political and philosophical thinking of people and on the rise of modern science based on experimental results."

This name will be accepted if no objections are raised within a period of 6 months.