Copernicium
Atomic Data
| Atomic Number | 112 |
| Symbol | Cn |
| Atomic Weight | 285 u |
| Density (STP) | N/A |
| Melting Point | N/A °C (None K) |
| Boiling Point | 83.85 °C (357 K) |
| Electronegativity | : |
| Electron Config. | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f14 6s2 6p6 6d10 7s2 |
| Oxidation States | +2 |
| Phase at STP | Gas |
| Category | Transition Metal |
| Period / Group | 7 / 12 |
| CAS Number | 54084-26-3 |
Electron Configuration
[Rn] 5f14 6d10 7s2
| Shell | n | Subshell | Electrons | Cumulative |
|---|---|---|---|---|
| K | 1 | 1s | 2 | 2 |
| L | 2 | 2s | 2 | 4 |
| L | 2 | 2p | 6 | 10 |
| M | 3 | 3s | 2 | 12 |
| M | 3 | 3p | 6 | 18 |
| M | 3 | 3d | 10 | 28 |
| N | 4 | 4s | 2 | 30 |
| N | 4 | 4p | 6 | 36 |
| N | 4 | 4d | 10 | 46 |
| N | 4 | 4f | 14 | 60 |
| O | 5 | 5s | 2 | 62 |
| O | 5 | 5p | 6 | 68 |
| O | 5 | 5d | 10 | 78 |
| O | 5 | 5f | 14 | 92 |
| P | 6 | 6s | 2 | 94 |
| P | 6 | 6p | 6 | 100 |
| P | 6 | 6d | 10 | 110 |
| Q | 7 | 7s | 2 | 112 |
| Total | 112 | 112 | ||
Isotopes of Copernicium
Copernicium is monoisotopic: ²⁸⁵Cn is its only naturally occurring stable isotope, accounting for 100% of all natural Copernicium.
| Isotope | Symbol | Protons | Neutrons | Abundance | Stability |
|---|---|---|---|---|---|
| Copernicium-285 | ²⁸⁵Cn | 112 | 173 | trace | Stable |
Abundance & Occurrence
Copernicium is present in Earth's crust at approximately trace amounts by mass and at approximately trace amounts by mass throughout the universe.
Earth's Crust (ppm by mass)
Universe (ppm by mass)
Discovery & History
Read more about the discovery of the periodic table of elements →
Safety & Handling
- Alpha radiation and short half-life: Copernicium isotopes are alpha emitters; Cn-285 (t½ = 29 s) is the longest-lived, allowing only the most rapid automated chemical studies.
- No practical bulk hazard: Only a few dozen atoms of copernicium have ever been synthesised; no macroscopic radiological or chemical hazard exists from the element.
- Noble-gas-like volatility: Theoretical and experimental evidence suggests Cn may be highly volatile and chemically inert; chemical characterisation experiments are conducted with gold-coated detectors at cryogenic temperatures to capture single atoms.
- Regulatory controls: All copernicium research is conducted at licensed heavy ion accelerator facilities under comprehensive radiation protection.
Copernicium in the Real World
Real-World Uses
- Relativistic chemistry experiments: Copernicium (Cn-285) gas-phase chromatography experiments conducted at GSI suggest it may behave more like a noble gas than mercury (its Group 12 homologue), due to extreme relativistic stabilisation of the 7s² electrons: one of the most striking demonstrations of relativistic effects on chemical behaviour.
- Nuclear physics and decay chain identification: Cn isotopes appear in the decay chains of flerovium (Z=114) and other superheavy elements, providing crucial data for verifying the synthesis of those species and mapping nuclear stability in the superheavy region.
- No commercial applications: Copernicium is produced a few atoms at a time; its most stable known isotope (Cn-285) has a half-life of about 29 seconds, making any practical application impossible.
Downloadable Resources
Free periodic table reference sheets for classrooms, study sessions, and laboratory use.
Frequently Asked Questions
Has copernicium ever been used for anything?
No. Copernicium has no practical applications. Its most stable isotope (Cn-285) has a half-life of about 30 seconds. It is produced only a few atoms at a time in particle accelerators and used exclusively for fundamental nuclear research. Some theoretical work suggests copernicium may have unusual chemical properties due to strong relativistic effects at Z=112.
What are the predicted unusual properties of copernicium?
Relativistic quantum mechanical calculations predict that copernicium may behave less like a metal (its group 12 neighbours are zinc, cadmium, and mercury) and more like a noble gas. The relativistic stabilisation of its 7s electrons is predicted to be so strong that copernicium may have a closed-shell electronic structure making it chemically inert, with a very low boiling point and possibly even existing as a gas at room temperature. Experiments to test this are extremely challenging given the few atoms available.
Is copernicium radioactive?
Yes, all isotopes of copernicium are radioactive. The most stable, Cn-285, has a half-life of about 30 seconds. It decays by alpha emission. All copernicium atoms are produced and decay almost immediately in particle accelerator experiments.
How did copernicium get its name?
Copernicium was named after Nicolaus Copernicus, the Polish astronomer who first proposed the heliocentric model of the solar system in 1543, fundamentally changing humanity's understanding of the universe. The element was synthesised at GSI Darmstadt in 1996, and the name was approved by IUPAC in 2010 to mark the 537th anniversary of Copernicus's birth.