Tennessine is a synthetic radioactive element with atomic number 117 and element symbol Ts. It is the second heaviest element created to date, with isotope half-lives less than one second. So, it is very rare and doesn’t stick around very long. Its name honors the home state of Oak Ridge National Lab (Tennessee), which played a significant role in the element’s discovery.
Basic Tennessine Facts
Atomic Number: 117
Element Symbol: Ts
Group: Group 17 (halogen group)
Period: Period 7
Element Family: Probably a metalloid, but with some halogen properties
Atomic Mass: 
Electron Configuration: [Rn] 5f14 6d10 7s2 7p5 (predicted)
Electrons per Shell: 2, 8, 18, 32, 32, 18, 7 (predicted)
Discovery: Joint Institute for Nuclear Research, Lawrence Livermore National Laboratory, Vanderbilt University and Oak Ridge National Laboratory (2009)
Name Origin: Named for Tennessee, the location of Oak Ridge National Laboratory (ORNL)
History of Discovery
In 2004, the Joint Institute for Nuclear Research (JINR) in Russia proposed a joint research venture in conjunction with Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee, United States, with the goal of synthesizing element 117. At the time, the undiscovered element had the placeholder name of ununseptium (Uus).
The plan involved a fusion reaction between a calcium-48 (element 20) beam and a berkelium (element 97) target. The reaction yields a number of products, including (they hoped) a few atoms of element 117. ORNL was the world’s only source of berkelium at the time, but production had halted because of the considerable expense of synthesizing the element. In 2008, after years of campaigning by Yuri Oganessian (leader of the JINR team) and Joseph Hamilton (Oganessian’s collaborator at Vanderbilt University), ORNL resumed producing californium, which made berkelium as a by-product. The price of production was $600,000.
While ORNL made the berkelium, JINR performed the actual fusion reaction. The berkelium had a half-life of only 330 days, so shipping it from the US to Russia was time-critical. But, Russian customs refused the package twice because of incomplete paperwork. Ultimately, the berkelium package crossed the Atlantic Ocean five times before finally gaining acceptance by Russia in June of 2009. The experiment immediately proceeded in late 2009 and the researchers announced the discovery of element 117 in 2010.
Confirmation of the discovery occurred in 2015. The International Union of Pure and Applied Chemistry (IUPAC) formally approved the name “tennessine” in 2016.
The name for element 117 honors Tennessee and Oak Ridge National Lab, which produced the superheavy isotopes critical for discovery of the latest elements on the periodic table.
The two known isotopes of tennessine are Ts-293 and Ts-294. They are both highly unstable (although much more stable than predicted) and decay in under a second.
Tennessine has no uses at the moment. In the future, it holds promise in research and in the synthesis of new elements.
Biological Role and Toxicity
Like other superheavy synthetic elements, tennessine serves no biological role. It is radioactive, but it’s compounds are not necessarily inherently toxic. However, the diatomic Ts2 may be irritants and toxic, similar to F2 or Cl2.
Sources of Tennessine
The element does not occur naturally and its production is expensive. Right at this instant, there is probably no tennessine in the world.
Most of the physical data for tennessine is predicted because it is a superheavy radioactive isotope that is very rare, expensive, and decays quickly.
State at STP: Solid (predicted)
Density (solid, at r.p.): 7.1-7.3 g/cm3 (predicted)
Melting Point: 623–823 K (350–550 °C, 662–1022 °F) (predicted)
Boiling Point: 883 K (610 °C, 1130 °F) (predicted)
Atomic Radius: 138 pm
Covalent Radius: 156–157 pm (predicted)
1st Ionization Energy: 742.9 kJ/mol
2nd Ionization Energy: 1435.4 kJ/mol
3rd Ionization Energy: 2161.9 kJ/mol
Oxidation States: (-1), (+1), (+3), (+5) (predicted)
Interesting Tennessine Facts
- While tennessine is in the halogen group, it is more metallic than the elements above it on the periodic table. Scientists predict it is a volatile, metallic-looking semimetal.
- Like other halogen elements, tennessine likely formed diatomic molecules (Ts2). TsH and TsCl are other probable molecules.
- The most common oxidation states for Tennessine are +1 (like other halogens) and also +3.
- Bonchev, D.; Kamenska, V. (1981). “Predicting the Properties of the 113–120 Transactinide Elements”. Journal of Physical Chemistry. 85 (9): 1177–1186. doi:10.1021/j150609a021
- Emsley, John (2011). Nature’s Building Blocks: An A-Z Guide to the Elements (New ed.). New York, NY: Oxford University Press. ISBN 978-0-19-960563-7.
- Fricke, Burkhard (1975). “Superheavy elements: a prediction of their chemical and physical properties”. Recent Impact of Physics on Inorganic Chemistry. Structure and Bonding. 21: 89–144. ISBN 978-3-540-07109-9. doi:10.1007/BFb0116498
- Oganessian, Yu.Ts.; Abdullin, F.Sh.; Bailey, P.D.; Benker, D.E.; Bennett, M.E.; Dmitriev, S.N.; et al. (2010). “Synthesis of a new element with atomic number Z = 117”. Physical Review Letters. 104 (14): 142502. doi:10.1103/PhysRevLett.104.142502
- Takahashi, N. (2002). “Boiling points of the superheavy elements 117 and 118”. Journal of Radioanalytical and Nuclear Chemistry. 251 (2): 299–301. doi:10.1023/A:1014880730282