Tennessine
Metalloid (predicted) · Period 7 · Group 17 · p-block
A halogen in name, a metal in prediction, made from American berkelium
- Atomic mass
- 294 u
- State at 25 °C
- Solid
- Electronegativity
- —
- Melting point
- 449.9 °Cpredicted
- Boiling point
- 609.9 °Cpredicted
- Configuration
- *[Rn] 5f14 6d10 7s2 7p5
Nucleus drawn at reduced count for clarity. Drag to rotate.
Tennessine, explained
Video lesson in production
Bhavya’s explainer for this element will play here.
Overview
Tennessine is the newest element to be discovered and sits in group 17 with the halogens, below fluorine, chlorine, bromine, iodine and astatine. Its predicted configuration is 7s2 7p5, one electron short of a filled shell, like the other halogens. But relativistic spin-orbit splitting separates its 7p orbitals so strongly that the expected halogen tendency to gain an electron and form a -1 ion is predicted to be weak.
Instead, tennessine is predicted to favor the +1 and +3 oxidation states and to behave more like a metalloid or metal than a classic halogen, continuing a trend already seen in astatine. These are predictions only; no chemical experiment has been done. Making tennessine requires berkelium-249, which has a half-life of 330 days and can be produced in useful amounts only in a few high-flux research reactors.
Discovery
Tennessine was made in 2009-2010 by a collaboration of Dubna, Oak Ridge National Laboratory, Lawrence Livermore, Vanderbilt University and the University of Tennessee. Oak Ridge irradiated curium in its High Flux Isotope Reactor for about 250 days, then purified 22 milligrams of berkelium-249, which was flown to Dubna and bombarded with calcium-48. Six atoms were reported in 2010. The name, approved in 2016, honors Tennessee.
- Where it’s found
- Tennessine does not occur in nature; it is made by bombarding berkelium-249 with calcium-48 ions in an accelerator.
- What it’s used for
- Superheavy element research
- Relativistic effects research
- Decay-chain identification
- Nuclear structure research
- In living things
- Tennessine has no biological role; it is radioactive and has only ever existed as individual atoms.
- Safety
- Radioactive and made only a few atoms ever; it decays within a fraction of a second.
How it compares
Where Tennessine sits among all 118 elements on the trends that shape the table.
- ElectronegativityNo data
Not measured for this element
- Ionization energyNo data
Not measured for this element
- Atomic radiusNo data
Not measured for this element
- Electron affinity166kJ/mol
#12 of 109 elements with data · predicted
- Density7.17g/cm³
#63 of 114 elements with data · predicted
- Melting point723K
#71 of 110 elements with data · predicted
- Density
- 7.17 g/cm³
- Atomic radius
- —
- Covalent radius
- —
- Molar heat
- —
- Appearance
- —
- Discovered by
- Joint Institute for Nuclear Research
Inside the atom
117 electrons arranged in 7 shells: 2 · 8 · 18 · 32 · 32 · 18 · 7.
Orbital diagram
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d10 7p5 · shorthand *[Rn] 5f14 6d10 7s2 7p5
- 1s2
- 2s2
- 2p6
- 3s2
- 3p6
- 4s2
- 3d10
- 4p6
- 5s2
- 4d10
- 5p6
- 6s2
- 4f14
- 5d10
- 6p6
- 7s2
- 5f14
- 6d10
- 7p5
Each box is an orbital holding up to two electrons of opposite spin. Highlighted subshells hold the valence electrons that decide how Tennessine bonds.
Signature reactions
How the first atoms were made, and how they fall apart.
Nuclear · Hot fusion
Discovery synthesis, 3n channel
Calcium-48 fuses with berkelium-249 and three neutrons evaporate, giving tennessine-294. One of the six atoms in the 2010 report came from this channel.
Conditions: calcium-48 beam on berkelium-249, Dubna U400 cyclotron, 2009-2010
Nuclear · Hot fusion
Discovery synthesis, 4n channel
With four neutrons evaporated the product is tennessine-293. Five of the first six atoms were this isotope.
Conditions: calcium-48 beam on berkelium-249, higher beam energy
Nuclear · Alpha decay
Alpha decay of tennessine-294
Tennessine-294 emits an alpha particle to become moscovium-290, which decays further through nihonium. These chains produced several previously unknown isotopes.
Conditions: spontaneous, half-life about 50 milliseconds
Where you’ll meet it
Tennessee
The U.S. state, home to Oak Ridge and Vanderbilt, gives element 117 its name.
Photo: Wikimedia Commons
Oak Ridge National Laboratory
Oak Ridge produced and purified the berkelium target needed to make tennessine.
Photo: Wikimedia Commons
High Flux Isotope Reactor
This Oak Ridge reactor made the berkelium-249 used as tennessine's target.
Photo: Wikimedia Commons
Great Smoky Mountains
Tennessee's best-known landscape stands for the state honored by element 117.
Photo: Wikimedia Commons
Research
No research on Tennessine yet
When Bhavya publishes a project that studies Tennessine, it will be linked here.