Tennessine

Tennessine is named after Tennessee, USA, home to Oak Ridge National Laboratory, Vanderbilt University and the University of Tennessee, all of which contributed to its synthesis. First produced in 2010 in a collaboration between JINR Dubna and US institutions.

• Atomic Number117117 protons, 117 electrons
• Atomic Mass294.211 uOver 117× 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
• Discovered2010First produced 2003s

What is Tennessine?

Ts-294 has a half-life of approx. 51 milliseconds. Sits below astatine in Group 17 (halogens) and is predicted to behave differently from other halogens due to relativistic effects. Named tennessine (Ts) in 2016.

With 117 protons, Tennessine sits in Group 17 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 Tennessine (Ts, element 117) 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 tennessine. Everything we know about it comes from detecting individual radioactive decays and theoretical calculations.

Where you find Tennessine

On Earth

Tennessine 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 Tennessine

Tennessine 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

Ts-294 has a half-life of approx. 51 milliseconds. Sits below astatine in Group 17 (halogens) and is predicted to behave differently from other halogens due to relativistic effects. Named tennessine (Ts) in 2016.

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