Periodic Table of Elements




Copernicium was first created on February 9, 1996, at the Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, Germany, by Sigurd Hofmann, Victor Ninov et al.

Name: Copernicium
Symbol: Cn
Atomic number: 112
Atomic weight: 285.17
State: unknown
Group, period, block: 12, 7, d
Color: unknown
Classification: transition metal
Electron configuration: 5f14 6d10 7s2

Physical properties

Density: 23.7 g/cm-3
Melting point: no data
Boiling point: no data

Atomic properties

Oxidation states: 4, 2, 0
Electronegativity: no data
Ionization energies: 1st: 1154.9 kJ·mol-1
Covalent radius: 122 pm
Van der Waals radius: no data
  • Cn
  • Electron Configuration


Copernicium is an artificial element, and thus a standard atomic mass cannot be given. Like all artificial elements, it has no stable isotopes. The first isotope to be synthesized was 277Cn in 1996. There are 6 known radioisotopes and 2 possible isomers. The longest-lived isotope is 285Cn with a half-life of 29 seconds.