On the periodic table, tennessine is the only element named after a U.S. state.
Tennessine has the symbol Ts and atomic number 117. It is a synthetic, highly radioactive element in group 17, the halogens. Only a very small number of atoms have been produced, and they decay rapidly, so its physical properties are known mainly through experiments and scientific predictions.
The name honors Tennessee, recognizing the state’s contributions to superheavy-element research, especially work connected with Oak Ridge National Laboratory, Vanderbilt University, and the University of Tennessee. The name was officially adopted in 2016.
Californium is named after the state and university associated with California, but its name refers to California rather than being the element named for a state in the same direct convention. Tennessine’s ending also follows the naming pattern used for halogens such as chlorine and astatine.