The synthetic element with atomic number 117 named after the U.S. state of Tennessee is tennessine.
Tennessine is a superheavy element in group 17 of the periodic table, the halogen group. Its symbol is Ts, and all known isotopes are radioactive and extremely short-lived. Because only tiny numbers of atoms have been produced, many of its physical properties are predicted rather than measured directly.
Researchers first reported the element in 2010 after a collaboration involving the Joint Institute for Nuclear Research in Russia and Oak Ridge National Laboratory, Vanderbilt University, and Lawrence Livermore National Laboratory in the United States. The International Union of Pure and Applied Chemistry approved the name tennessine in 2016.
The name honors Tennessee’s contributions to superheavy-element research and nuclear science. Tennessine is not found naturally in useful quantities; it is created by nuclear reactions and studied one atom at a time.