ELEMENTLE

Element 113 · Metal

Nihonium

Period 7 · Group 13

Nihonium is a chemical element with atomic number 113. It has a symbol Nh. It is a synthetic element (an element that can be created in a laboratory but is not found in nature) and is extremely radioactive; its most stable known isotope, nihonium-286, has a half-life of 20 seconds.

Three reasons Nihonium stands out

  1. 1

    Synthetic element, named after Japan.

  2. 2

    It was the first element to be discovered by an Asian research team, at the RIKEN institute in 2004.

  3. 3

    It took nearly a decade of further research and three confirmed decay chains before its discovery was officially recognised.

Japan’s name on the periodic table

Nihonium was the first element credited to a team in Asia. Researchers at RIKEN painstakingly linked a few atoms through characteristic decay chains before recognition was secured. Nihon is one Japanese name for Japan, so the element’s name records both place and scientific milestone.

Nihonium at a glance
Atomic number / protons113
SymbolNh
Family (Elementle)Metal
Classification (PubChem)Post-transition metal
Period7
Group13
Atomic mass (u)286.182
Standard stateBulk state not experimentally established
Electron configuration[Rn]5f14 6d10 7s2 7p1 (predicted)
Reported oxidation statesNot available
Electronegativity (Pauling)Not available
Atomic radius (pm)Not available
First ionization energy (eV)Not available
Electron affinity (eV)Not available
Density (g/cm³)Not available
Melting pointNot available
Boiling pointNot available
Discovery (PubChem)2004

Values are reference data, not a specification for every temperature, pressure, or allotrope. Unknown properties are left unavailable. Superheavy-element predictions remain uncertain.

Sources & further reading

PubChem: Nihonium · Nihonium on Wikipedia

The introduction and original editorial story are adapted from Wikipedia contributors via Periodic-Table-JSON. Element descriptions and their adaptations are available under CC BY-SA 3.0. Numerical attributes use the PubChem periodic-table dataset, retrieved September 22, 2026.