Nihonium (Nh)

Nihonium (symbol Nh) is the chemical element with atomic number 113: a superheavy element whose properties are still unknown, radioactive, made artificially, with an atomic mass of 286 u. Discovered in 2004 (Kosuke Morita et al. (RIKEN)).

Nihonium takes its name from Nihon, “Japan” in Japanese. It was created by Kosuke Morita's team at RIKEN, near Tokyo, which observed just three atoms over nine years of effort. It is the first element discovered in an Asian country. Its most stable known isotope, nihonium-286, has a half-life of about ten seconds.

Key facts

Atomic number: 113
Symbol: Nh
French name: Nihonium
Atomic mass: 286 u
Molar mass: [286] g/mol
Family: Unknown properties
Position: period 7, group 13, p-block
State at 0 °C: Unknown
First ionization energy: 705 kJ/mol
Electron configuration: [Rn] 5f¹⁴ 6d¹⁰ 7s² 7p¹
Radioactive: yes
Discovery: 2004, Kosuke Morita et al. (RIKEN)

Origin of the name

From Nihon, “Japan” in Japanese.

What does nihonium look like?

Never observed; predicted to be a heavy metal, perhaps similar to thallium.

Where is nihonium found?

Absent from nature.

How is nihonium produced?

RIKEN bombards a bismuth-209 target with zinc-70 ions, an extremely unlikely reaction: tens of billions of billions of zinc ions had to be fired to obtain each atom. Dubna has also observed it as a decay product of moscovium.

Top producers

Japan (RIKEN)
Russia (Dubna)

What is nihonium 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 nihonium

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 nihonium

RIKEN detected a first atom in July 2004, a second in April 2005, then a third — the decisive one — in August 2012. Dubna and Livermore had reported atoms of 113 as early as 2003–2004 through the decay of element 115, but IUPAC credited the discovery to RIKEN at the end of 2015. The name nihonium became official in 2016.

Did you know?

In all, the zinc beam ran for the equivalent of more than 500 days to produce those three atoms.
“Nihon” literally means “origin of the sun”: Japan is the “land of the rising sun.”
It is the first element discovered outside Europe and North America.

Isotopes of nihonium

No stable isotopes; it took nine years of effort in Japan to observe three atoms of nihonium-278.

nihonium-278: radioactive, half-life 1.4 ms. Synthesized in Japan (RIKEN) in 2004; the basis for recognizing the discovery.
nihonium-286: radioactive, half-life 9.5 s. The longest-lived known, a decay product of moscovium.

Related elements

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

Same column (group 13): Boron (B), Aluminium (Al), Gallium (Ga), Indium (In), Thallium (Tl).