Copernicium

Copernicium is named after Nicolaus Copernicus, the astronomer who placed the Sun at the centre of the solar system. Remarkably, relativistic quantum mechanical predictions suggest it may be a gas at room temperature rather than a metal: the first elemental metal predicted to be gaseous.

• Atomic Number112112 protons, 112 electrons
• Atomic Mass286.179 uOver 112× heavier than hydrogen
• State at Room TempExpected to be a Solidpredicted solid
• DensityNot measuredPredicted from periodic trends
• Melting / BoilingNot yet measuredDecays in milliseconds to hours
• Discovered1996First produced 1988s

What is Copernicium?

Cn-285 has a half-life of approx. 29 seconds. First produced in 1996 at GSI. Named after Copernicus. Sits below mercury in Group 12. Calculations suggest relativistic effects may make copernicium and mercury behave more like noble gases than metals.

With 112 protons, Copernicium sits in Group 12 of the periodic table, Period 7, in the superheavy transactinide region. Its properties are predicted largely from theory and from single-atom chemistry experiments, not from bulk measurements.

Fact Copernicium (Cn, element 112) has only ever been produced a few atoms at a time. Each atom decays within milliseconds. No one has ever seen, touched or measured a weighable amount of copernicium. Everything we know about it comes from detecting individual radioactive decays and theoretical calculations.

Where you find Copernicium

On Earth

Copernicium does not exist naturally. It is made only artificially in nuclear physics laboratories by firing beams of one heavy nucleus at another and watching for the rare collisions that fuse them together. The main laboratories capable of producing superheavy elements are JINR in Dubna (Russia), GSI in Darmstadt (Germany), RIKEN in Japan and Lawrence Livermore National Laboratory in California.

How we use Copernicium

Copernicium has no practical uses. Only a handful of atoms have ever been produced, each existing for a fraction of a second to a few minutes. Research focuses on understanding nuclear structure, testing theoretical models of the atom, and searching for the predicted "island of stability", a region of superheavy nuclei that may be significantly longer-lived than those currently known.

How it was discovered

Cn-285 has a half-life of approx. 29 seconds. First produced in 1996 at GSI. Named after Copernicus. Sits below mercury in Group 12. Calculations suggest relativistic effects may make copernicium and mercury behave more like noble gases than metals.

Deeper dive: superheavy elements and the island of stability

Nuclear physicists predict that certain combinations of protons and neutrons, "magic numbers", create particularly stable nuclei. For superheavy elements, a theoretical "island of stability" is predicted around element 114 (flerovium) or beyond, where nuclei with the right magic number of neutrons might have half-lives of years or even longer rather than milliseconds. So far, the search continues. Elements 113-118 were all officially confirmed and named in 2016, completing Period 7 of the periodic table. Whether an eighth period of elements beyond oganesson (118) can ever be made and studied remains one of the great open questions in chemistry and nuclear physics.

Superheavy elements are made by accelerating beams of lighter nuclei (often calcium-48, because of its convenient doubly-magic structure) to high energies and firing them at heavy targets (lead, bismuth, uranium, curium, californium). Very rarely, two nuclei fuse instead of bouncing apart. The fusion product is detected by its characteristic radioactive decay chain, a signature sequence of alpha decays each producing a known element, counted backwards to identify the original product.

Moving to 113 protons on the periodic table brings us to the next superheavy element.