Tennessine (Ts)

Tennessine (symbol Ts) is the chemical element with atomic number 117: a superheavy element whose properties are still unknown, radioactive, made artificially, with an atomic mass of 294 u. Discovered in 2010 (Dubna, Oak Ridge and Vanderbilt laboratories).

Tennessine, discovered in 2010, is the most recent addition to the periodic table. Its name honors the state of Tennessee, home to Oak Ridge National Laboratory, Vanderbilt University and the University of Tennessee, which helped create it together with Dubna. Placed in the halogen column (like chlorine or iodine), it would actually behave more like a metalloid. Its most stable known isotope, tennessine-294, lives about 50 milliseconds.

Key facts

Atomic number: 117
Symbol: Ts
French name: Tennesse
Atomic mass: 294 u
Molar mass: [294] g/mol
Family: Unknown properties
Position: period 7, group 17, p-block
State at 0 °C: Unknown
First ionization energy: 743 kJ/mol
Electron configuration: [Rn] 5f¹⁴ 6d¹⁰ 7s² 7p⁵
Radioactive: yes
Discovery: 2010, Dubna, Oak Ridge and Vanderbilt laboratories

Origin of the name

From Tennessee, a US state.

What does tennessine look like?

Never observed; predicted to be a solid with a metallic or semimetallic look.

Where is tennessine found?

Absent from nature.

How is tennessine produced?

Dubna bombarded a berkelium-249 target, made at Oak Ridge (22 milligrams, after months in a reactor), with calcium-48 ions. Speed was essential: berkelium-249 loses half its atoms in less than a year.

Top producers

Russia (Dubna)
United States (Oak Ridge, Vanderbilt, Livermore)

What is tennessine used for?

Basic research only

In everyday life

None — it exists only for moments in the lab

Role in living things

No biological role.

Hazards of tennessine

Radioactive, but produced atom by atom: no practical danger.

Cosmic origin

Human-made: Does not exist (or barely) in nature: synthesized in a reactor or accelerator.

History of tennessine

In April 2010, the Dubna–Oak Ridge–Vanderbilt–Livermore collaboration announced six atoms of element 117. GSI confirmed the discovery in 2014. The name tennessine, with the “-ine” ending of the halogens, was adopted in 2016.

Did you know?

Without Oak Ridge's berkelium, which only a few reactors in the world can produce, this element could not have been created.
Its decay chain revealed lawrencium-266, the longest-lived lawrencium isotope known (about 11 hours).
It is the only element whose name evokes a US state other than California.

Isotopes of tennessine

No stable isotopes; only about twenty atoms of tennessine have been produced, using an American berkelium target.

tennessine-293: radioactive, half-life 22 ms. The element's first synthesized isotope, in 2010.
tennessine-294: radioactive, half-life 51 ms. The longest-lived known, observed at the same time.

Related elements

Same family (unknown properties): Meitnerium (Mt), Darmstadtium (Ds), Roentgenium (Rg), Copernicium (Cn), Nihonium (Nh), Flerovium (Fl), Moscovium (Mc), Livermorium (Lv), Oganesson (Og).

Same column (group 17): Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I), Astatine (At).