Tennessine (formerly Ununseptium meaning "one-one-seven-ium" in Latin) is a radioactive superheavy man-made chemical element. It has a symbolTs and atomic number of 117. It is the second heaviest element of all, and is the second to last element. It is in group 17 in the periodic table, where the halogens are. Its properties are not yet fully known but it is probably a metalloid. The discovery of tennessine was announced in 2010 by scientists in Russia and the United States. They collaborated and it is the most recently discovered element as of 2019. It is named after the state of Tennessee and it has no uses except research.
↑ 3.03.13.23.33.43.5Hoffman, Darleane C.; Lee, Diana M.; Pershina, Valeria (2006). "Transactinides and the future elements". In Morss; Edelstein, Norman M.; Fuger, Jean (eds.). The Chemistry of the Actinide and Transactinide Elements (3rd ed.). Dordrecht, The Netherlands: Springer Science+Business Media. ISBN978-1-4020-3555-5.
↑ 6.06.16.2Chang, Zhiwei; Li, Jiguang; Dong, Chenzhong (2010). "Ionization Potentials, Electron Affinities, Resonance Excitation Energies, Oscillator Strengths, And Ionic Radii of Element Uus (Z = 117) and Astatine". J. Phys. Chem. A. 2010 (114): 13388–94. Bibcode:2010JPCA..11413388C. doi:10.1021/jp107411s.
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Royal Society of Chemistry (2016). "Tennessine". rsc.org. Royal Society of Chemistry. Retrieved 9 November 2016. A highly radioactive metal, of which only a few atoms have ever been made.
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GSI (14 December 2015). "Research Program – Highlights". superheavies.de. GSI. Retrieved 9 November 2016. If this trend were followed, element 117 would likely be a rather volatile metal. Fully relativistic calculations agree with this expectation, however, they are in need of experimental confirmation.