Copernicium is a periodic table with symbol Cn and atomic number 112. It is an extremely radioactive synthetic that can only be created in a laboratory. It's longest-lived isotope is Cn-285.
After acknowledging their discovery, the IUPAC asked the discovery team at GSI to suggest a permanent name for element 112. On 14 July 2009, they proposed copernicium with the element symbol Cn, after Nicolaus Copernicus "to honor an outstanding scientist, who changed our view of the world".