Copernicium Facts – Element Symbol Cn or Atomic Number 112

Copernicium is a synthetic radioactive element with the atomic number 112 and the symbol Cn. It is a short-lived superheavy element that belongs to Group 12 of the periodic table, placing it below zinc, cadmium, and mercury. Due to its position in the periodic table, it likely exhibits some properties similar to its lighter homologs, though relativistic effects significantly alter its chemistry. Because it is highly unstable and only comes from nuclear laboratories, copernicium has no known natural occurrence or practical applications.

History of Discovery

Synthesis and First Detection

Copernicium was first synthesized on February 9, 1996, by a team of scientists at the Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, Germany. The team, led by Sigurd Hofmann, Victor Ninov, and Peter Armbruster, created copernicium by bombarding a lead-208 (²⁰⁸Pb) target with high-energy zinc-70 (⁷⁰Zn) nuclei using a linear accelerator. The nuclear fusion reaction is:

₈₂²⁰⁸Pb + ₃₀⁷⁰Zn → ₁₁₂²⁷⁸Cn∗ → ₁₁₂²⁷⁷Cn + n

This reaction produced an atom of copernicium-277, which decayed via alpha emission with a half-life of about 0.24 milliseconds.

Verification and Naming

Following the initial synthesis, independent experiments at RIKEN (Japan) and Lawrence Berkeley National Laboratory (USA) confirmed the existence of copernicium in the early 2000s. In 2009, the International Union of Pure and Applied Chemistry (IUPAC) officially recognized the discovery.

The element was initially given the temporary name “ununbium” (Uub) following IUPAC’s standard naming conventions for new elements. However, on February 19, 2010, IUPAC approved the name copernicium (Cn) in honor of Nicolaus Copernicus (1473–1543), the Polish astronomer who proposed the heliocentric model of the solar system.

While the GSI team proposed the symbol “Cp” for the new element, the IUPAC rejected the symbol because it had a previous association with the element lutetium, which had previously been known as cassiopeium with symbol Cp.

Synthesis and Isolation

Copernicium does not occur nature and can only be produced in nuclear reactors or particle accelerators. The most successful method of synthesis involves heavy ion fusion reactions, primarily using lead or bismuth targets bombarded with zinc or nickel ions.

Predicted Appearance

Since there are no visible samples of copernicium, its appearance is uncertain. However, theoretical calculations suggest it is a dense, metallic solid at room temperature. Unlike mercury, which is a liquid, copernicium is predicted to have a higher melting and boiling point due to its stronger metallic bonding.

Periodic Table Placement and Element Group

Copernicium is part of the d-block of the periodic table and belongs to Group 12, which includes zinc (Zn), cadmium (Cd), and mercury (Hg). However, due to its high atomic number (112) and relativistic effects on its electrons, copernicium displays significant deviations in properties compared to its lighter homologs.

Comparison to Other Group 12 Elements

Comparison With Other Period 7 d-Block Elements

Copernicium is part of the 7th period d-block, alongside roentgenium (Rg, Z=111) and nihonium (Nh, Z=113). All these elements experience strong relativistic effects, altering their expected chemical behavior.

Unlike roentgenium, which likely behaves like gold, copernicium’s low reactivity makes it more similar to oganesson (Og, Z=118) than mercury. Due to relativistic effects, copernicium’s metallic bonding is weaker, potentially making it volatile like a noble gas rather than a typical metal.

Chemical Behavior

• Copernicium exhibits less metallic character than mercury.
• It forms simple Cn²⁺ cations, analogous to Hg²⁺.
• Compounds include CnF₂ (copernicium fluoride) and CnCl₂ (copernicium chloride).
• Unlike mercury, it exhibits low reactivity, behaving similarly to radon (Rn).

Oxidation States

Copernicium likely favors a +2 oxidation state, similar to mercury (Hg²⁺). However, more recent theoretical studies and calculations suggest that copernicium also exhibits a +4 or even +6 oxidation state in compounds such as CnF₆ (copernicium hexafluoride).

• +2: The most stable and expected state, analogous to Zn²⁺, Cd²⁺, and Hg²⁺.
• +4: Predicted in some fluorides (e.g., CnF₄), suggesting that copernicium’s 6d orbitals might participate in bonding.
• +6: Theoretical models indicate that CnF₆ may be stable, implying that copernicium can achieve a higher oxidation state than mercury, behaving more like transition metals.

These findings suggest that copernicium is more reactive than initially believed, forming stronger chemical bonds than its lighter homologs. This challenges some predictions that Cn behaves like a noble gas and opens the possibility for more complex chemical interactions.

Isotopes

Copernicium has no stable isotopes, and only a few radioisotopes have been synthesized. The most notable ones include:

Uses of Copernicium

Due to its extreme instability, copernicium has no practical uses outside of scientific research. It is mainly used for studying relativistic effects and nuclear stability in superheavy elements.

Copernicium’s Role in the Island of Stability

The island of stability is a theoretical concept in nuclear physics predicting that certain superheavy nuclei with a “magic number” of protons and neutrons may have significantly longer half-lives than currently known elements.

Is Copernicium Close to the Island of Stability?

• Copernicium’s known isotopes (e.g., ²⁸⁵Cn, ²⁸³Cn) have half-lives measured in seconds, which is longer than many neighboring elements.
• Predictions place the island of stability at Z ≈ 114–120 and N ≈ 184, meaning copernicium is near, but not within, this region.
• Heavier isotopes of copernicium with more neutrons (e.g., ²⁹⁰Cn or ²⁹⁴Cn) might have significantly longer lifetimes.

Biological Role and Toxicity

• Biological Role: Copernicium has no biological function and does not occur naturally.
• Toxicity: As a radioactive element, it is highly hazardous, although its extreme instability, rarity, and mode of decay prevents any realistic exposure risk.

Key Copernicium Facts

Interesting Copernicium Facts

• First element named after an astronomer—Nicolaus Copernicus.
• Most relativistic element in Group 12, causing unusual chemical behavior.
• Initially thought to be gaseous, but later calculations suggest a dense metal.
• One of the heaviest elements synthesized, with atomic number 112.
• Most stable isotope (²⁸⁵Cn) lasts 29 seconds, which is not a long time but still places the element near the “island of stability”.

References

• Eichler, R.; et al. (2007). “Chemical Characterization of Element 112”. Nature. 447 (7140): 72–75. doi:10.1038/nature05761
• Hofmann, S.; et al. (1996). “The new element 112”. Zeitschrift für Physik A. 354 (1): 229–230. doi:10.1007/BF02769517
• Karol, P. J.; Nakahara, H.; Petley, B. W.; Vogt, E. (2001). “On the Discovery of the Elements 110–112”. Pure and Applied Chemistry. 73 (6): 959–967. doi:10.1351/pac200173060959
• Oganessian, Yu. Ts. (2004). “Superheavy elements”. Physics World. 17 (7): 25–29. doi:10.1088/2058-7058/17/7/31