Periodic Table of Elements

112

Copernicium

285.17

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
2,8,18,32,32,18,2

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

Isotopes

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.