Copernicium's atomic number is 113 and its symbol is Cn. Its known isotopes are extremely radioactive and have only been created in a laboratory. The most stable known isotope, copernicium-285, has a half-life of approximately 28 seconds. It is named after the astronomer Nicolaus Copernicus, and it was first created in 1996 by the GSI Helmholtz Centre for Heavy Ion Research near Darmstadt, Germany. Copernicium is calculated to have several properties that differ from its lighter homologs in group 12, and it may have more similarities to the noble gases such as radon. Predictions vary on whether solid copernicium would be a metal, semiconductor, or insulator. This display is contained within crystal clear Lucite acrylic.