ElementsWhat is copernicium?
Copernicium is a radioactive element made in particle accelerators, a few atoms at a time.
What is copernicium used for?
Research only.
Where the name comes from
In honour of the astronomer Nicolaus Copernicus.
Key facts
- Symbol
- Cn
- Atomic number
- 112
- Atomic mass
- 286.179 u
- Family
- Transition metal
- Period
- 7
- Group
- 12
- Block
- d
- State at room temperature
- Solid (expected)
- Melting point
- not measured
- Boiling point
- not measured
- Density
- not measured
- Electrons per shell
- 2, 8, 18, 32, 32, 18, 2
- Electron configuration
- [Rn]7s2 5f14 6d10
- Common oxidation states
- 2, 1, 0
- Electronegativity (Pauling)
- no value
- First ionisation energy
- not measured
- Electron affinity
- no value
- Atomic radius (van der Waals)
- no value
- Discovered
- 1996
Place in the periodic table
Copernicium is element number 112. It sits in period 7 (row 7) of the periodic table, in group 12 (column 12), and belongs to the d-block. Just before it comes roentgenium (111), and just after it comes nihonium (113). In the same column, mercury is above it. Elements in one column tend to behave alike.
Family: Transition metals.
Physical properties
Too few atoms of copernicium have been made to measure its bulk properties. It is expected to be a solid at room temperature.
Inside the atom
An atom of copernicium has 112 protons in its nucleus and, when neutral, 112 electrons around it. The electrons are arranged in 7 shells: 2, 8, 18, 32, 32, 18, 2. The outermost shell holds 2 electrons. Written in full, the electron configuration is [Rn]7s2 5f14 6d10 (predicted).
One mole of copernicium weighs 286.179 grams, so a single gram contains about 2.10 × 1021 atoms.
The ring picture is a simple model that only counts the electrons in each shell. Real atoms do not look like this.
Next steps
- Work out the weight of a compound that contains copernicium with the molar mass calculator.
- Compare it with every other element in the sortable list.
- Test yourself with the symbol quiz.
Figures on this page are from PubChem (U.S. National Library of Medicine), as downloaded on 11 November 2026. See About and data sources.