Overview

Tennessine is a synthetic, highly radioactive superheavy chemical element with the symbol Ts and atomic number 117. It occupies Group 17 of the periodic table, the column that contains the halogens, although its exact chemical behavior remains largely theoretical. Only a handful of atoms of tennessine have ever been produced, and all known isotopes are unstable with very short half-lives. Because it must be created in particle accelerators and decays quickly, tennessine has no commercial applications and is studied exclusively for basic science.

Characteristics and predicted properties

Direct experimental data on tennessine's physical or chemical properties are extremely limited. Predictions based on quantum theory and relativistic effects suggest an electron configuration close to [Rn]5f14 6d10 7s2 7p5, placing it among the halogens. However, strong relativistic effects at such high atomic number may alter its behavior so that it shows some metallic or metalloid characteristics rather than behaving exactly like lighter halogens. Researchers describe these expectations cautiously: tennessine may exhibit properties intermediate between a nonmetal and a metalloid, and its chemistry could differ from simple extrapolations of periodic trends.

  • Symbol: Ts (Ts).
  • Atomic number: 117 (117).
  • Group: 17 (halogens) (group 17).
  • Nature: synthetic and radioactive; only produced in minute quantities.
  • Predicted electron configuration and relativistic effects influence its chemistry (metalloid predictions).

History of discovery

The first announced synthesis of element 117 was reported in 2010 by an international collaboration of scientists from Russia and the United States. The experimental work involved target and accelerator facilities in Russia with support and participating laboratories in the U.S., reflecting a multinational effort in superheavy-element research (Russia, United States, collaboration). Following peer review and additional confirmation, the element received its permanent name, tennessine, in 2016. The name honors the U.S. state of Tennessee for contributions from its research institutions to the discovery and to heavy-element science more broadly.

Production and isotopes

Tennessine is produced in heavy-ion fusion reactions in specialized facilities. Experiments typically fuse a heavy actinide target with a lighter projectile; the resulting compound nucleus, after emitting one or more neutrons, can form an isotope of element 117. Only a very small number of atoms have been created, and the observed isotopes decay through alpha emission and spontaneous fission. Reported isotopes have extremely short half-lives, ranging from milliseconds to at most a few seconds, which limits experimental study to detection of decay chains and indirect measurements.

Uses, significance, and notable distinctions

Because of its fleeting existence and the difficulty of producing it, tennessine has no practical or commercial uses. Its primary significance lies in advancing fundamental knowledge of nuclear physics and chemistry: synthesizing the heaviest elements tests models of nuclear stability, helps map the limits of the periodic table, and probes how relativistic effects reshape chemical behavior at extreme atomic numbers. Tennessine also illustrates the international nature of modern elemental discovery and is among the most recently named elements, with a temporary systematic name of ununseptium (Uus) used before the official name was approved.

Further reading and resources

Research on tennessine is ongoing and combines experimental nuclear techniques with theoretical chemistry. For introductions and summaries produced by scientific organizations and research institutions, see external resources and reviews linked by research centers that participated in or commented on the discovery (element overview, Russian laboratory reports, U.S. partner summaries). Additional background on periodic trends and relativistic effects can be found through general chemistry and nuclear physics references (group 17 context, prediction studies, collaboration histories).