Tennessine

properties predicted

Tennessine (Ts) is a superheavy element with atomic number 117. It has no stable isotope and no characteristic isotopic composition on Earth, so it has no standard atomic weight; its longest-lived isotope has mass number 294. Its electron configuration is predicted to be [Rn] 5f14 6d10 7s2 7p5, which gives it 7 valence electrons.

Tennessine key data

Symbol	Ts
Atomic number	117
Mass number (longest-lived isotope)	294
Protons	117
Neutrons (longest-lived isotope, tennessine-294)	177
Electrons (neutral atom)	117
Valence electrons	7
Category	Unknown
Period	7
Group	17
Block	p-block
Noble gas notation	[Rn] 5f14 6d10 7s2 7p5
Full electron configuration	1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f14 6s2 6p6 6d10 7s2 7p5
Electrons per shell	2, 8, 18, 32, 32, 18, 7

Mass number: IUPAC CIAAW radioactive elements, from NUBASE2020.

Properties of tennessine

From PubChem, the US National Institutes of Health. Public domain. Most properties of this element are predicted, because only a few atoms have ever been made.

Predicted state at room temperature	Solid
Predicted oxidation states	+5, +3, +1, −1
Discovered	2010

Tennessine electron configuration

The full electron configuration of tennessine is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f14 6s2 6p6 6d10 7s2 7p5. With the noble-gas core collapsed it is [Rn] 5f14 6d10 7s2 7p5, and the outermost subshell is 7p5.

Bohr model of tennessine (Ts): a nucleus and seven shells holding 2, 8, 18, 32, 32, 18 and 7 electrons from the inside out. — Bohr model of tennessine (Ts). Image © ScienceQuest, CC BY 4.0: free to reuse with credit to ScienceQuest and a link to this page, as the image licence explains.

Orbital box diagram of tennessine (Ts), [Rn] 5f14 6d10 7s2 7p5, with the radon core drawn as one bar: one box per orbital, filled by Hund’s rule, showing one unpaired electron, in 7p. — Orbital diagram of tennessine (Ts). Image © ScienceQuest, CC BY 4.0: free to reuse with credit to ScienceQuest and a link to this page, as the image licence explains.

Why group and block follow from this is set out in how the periodic table maps electron configuration, and the electron configuration of every element is listed on one page.

Mass of one tennessine atom

A molar mass is grams per mole, so dividing by the Avogadro constant gives the mass of a single atom, or for an element with more than one natural isotope the average mass of its atoms, and the reciprocal gives how many atoms sit in a gram.

Mass of one atom

one atom = 294 / (6.02214076 × 10²³)
= 4.8820 × 10⁻²² g

Atoms in one gram

atoms per gram = 6.02214076 × 10²³ / 294
= 2.0483 × 10²¹ atoms

Tennessine has no standard atomic weight, because it has neither a stable isotope nor a characteristic isotopic composition on Earth. The figure used above is the mass number of tennessine-294, so treat these as nominal.

Tennessine on the periodic table

Tennessine is in period 7, group 17, in the p-block.

The other elements of group 17 are fluorine, chlorine, bromine, iodine and astatine.