Nuclides
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Chemical element · Atomic number 112
Copernicium (Cn)
Transition metals · Period 7 · Unknown / not established
For superheavy elements, many atomic and bulk properties are predictions. Unknown physical states stay unknown; listed estimates are not evidence of bulk measurements.
Element identity
- Atomic number (Z)
- 112
- Symbol
- Cn
- Atomic weight / isotope mass number
- [285]
- Category
- Transition metals
- Physical state (reference)
- Unknown / not established
- Period
- 7
- Group (reference)
- 12
- Block
- d
Physical properties
- Appearance
- Not available
- Density
- 23.7 g·cm⁻³ (predicted; not a bulk measurement)
- Melting point
- Not available
- Boiling point
- 357 (+112−108) K / 84 (+112−108) °C / 183 (+202−194) °F (predicted; not a bulk measurement)
- Sublimation point
- Not available
Atomic and material properties
- Electron configuration
- [Rn] 5f¹⁴ 6d¹⁰ 7s²
- Electrons per shell
- K2 L8 M18 N32 O32 P18 Q2
- Oxidation states
- 4, 2, 1, 0
- Electronegativity (Pauling)
- Not available
- Atomic radius
- Not available
- Covalent radius
- 122 pm
- Molar ionization energies
- 1st: 1154.9 kJ·mol⁻¹ 2nd: 2170.0 kJ·mol⁻¹ 3rd: 3164.7 kJ·mol⁻¹ 4th: 4245.4 kJ·mol⁻¹ 5th: 5499.7 kJ·mol⁻¹
- Thermal conductivity
- Not available
- Molar heat capacity
- Not available
- Crystal structure
- Hexagonal close-packed
- CAS number
- 54084-26-3
Property source: Wikipedia — Copernicium, adapted from the Nuclides App snapshot. Quoted conditions and qualifiers are retained.
Sources and interpretation
Snapshot exported 24 October 2026 from the element assets used by Nuclides. Properties are a reference compilation, not a new evaluation. Missing values are shown as “Not available”. Density and phase depend on temperature, pressure and allotrope; retained conditions are part of the quoted property.
Atomic weight is dimensionless. Parentheses give uncertainty in the last quoted digits. A single integer in square brackets is an isotope mass number, not a standard atomic weight. The snapshot can differ from current evaluations; consult CIAAW standard atomic weights and the IUPAC periodic table for current values and conventions.
Element properties in the App snapshot are adapted from Wikipedia. Each element page links to its source article; text adaptations are available under CC BY-SA 4.0. No third-party images are included.
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