Element 113: Nihonium (Nh), Its Discovery and Name
Last reviewed on 1 October 2026.
Element 113 is nihonium (symbol Nh), a synthetic superheavy element first made at RIKEN in Japan on 23 July 2004 and named after Japan ("Nihon") in 2016. It sits in group 13 and period 7 of the periodic table, below thallium. Nihonium does not occur in nature: every known isotope decays within seconds, and only a handful of atoms have ever been produced. It is the first element discovered in Asia.
Element 113 at a Glance
| Name and symbol | Nihonium, Nh |
| Atomic number | 113 (113 protons) |
| Former placeholder name | Ununtrium (Uut) |
| Position | Group 13, period 7, p-block |
| Neighbours | Copernicium (112) to the left, flerovium (114) to the right, thallium (81) above |
| Occurrence | Synthetic only; not found in nature |
| Longest-lived known isotope | Nihonium-286, half-life of roughly 10 seconds |
| Discovered by | RIKEN Nishina Center team led by Kosuke Morita (Wako, Japan) |
| First atom detected | 23 July 2004 |
| Discovery credited by IUPAC | 30 December 2015 |
| Name approved | 28 November 2016 |
For a closer look at where nihonium sits in the table and how it compares with the rest of group 13, see element 113 on the periodic table. For its isotopes, half-lives and predicted chemistry, see nihonium properties and isotopes.
When Was Element 113 Discovered?
Element 113 was not discovered on a single day. It took years of experiments, three detected atoms and a formal review before credit was assigned. The key dates:
| Date | Event |
|---|---|
| 2003 | RIKEN begins its search for element 113 using its linear accelerator (RILAC) and the GARIS separator. |
| February 2004 | A collaboration of the Joint Institute for Nuclear Research (JINR, Dubna, Russia) and Lawrence Livermore National Laboratory (USA) reports element 115 made from americium-243 and calcium-48, with element 113 appearing in its alpha-decay chains. |
| 23 July 2004 | RIKEN detects its first atom of element 113 (nihonium-278), made by fusing zinc-70 with bismuth-209. |
| 2 April 2005 | RIKEN detects a second atom. |
| 12 August 2012 | A third RIKEN atom decays through a chain that ends in already well-known isotopes, giving the strongest proof of identity. |
| 30 December 2015 | IUPAC announces that the joint IUPAC/IUPAP working party credits RIKEN with the discovery of element 113, along with the discoveries of elements 115, 117 and 118 by other teams. |
| 8 June 2016 | IUPAC publishes the proposed name nihonium (Nh) for a five-month public review. |
| 28 November 2016 | IUPAC formally approves the name nihonium and symbol Nh. |
Who Found Nihonium?
Nihonium was found by a team at the RIKEN Nishina Center for Accelerator-Based Science in Wako, near Tokyo, led by nuclear physicist Kosuke Morita. The team accelerated zinc-70 ions to roughly a tenth of the speed of light and fired them at a thin bismuth-209 target:
70Zn + 209Bi → 278Nh + 1 neutron
Fusion of this kind is extraordinarily rare, which is why it took about nine years of experiments to collect three atoms. Each atom was identified not directly but through its chain of alpha decays: nihonium-278 → roentgenium-274 → meitnerium-270 → bohrium-266 → dubnium-262 and beyond. The 2012 chain reached isotopes whose properties were already known, which tied the starting atom firmly to element 113.
The competing Dubna–Livermore claim
The JINR–Livermore team saw element 113 atoms earlier, as decay products of element 115 (now moscovium). The international working party that reviewed the evidence concluded that, at the time, those results did not yet meet the criteria for discovery, partly because the decay chains did not connect to known nuclei. Credit, and with it the right to propose a name, went to RIKEN. The Dubna–Livermore collaboration (with Oak Ridge and Vanderbilt for element 117) was credited with elements 115, 117 and 118.
History of Naming Element 113
- Placeholder name: under IUPAC's systematic rules, undiscovered or unnamed elements get a Latin-based name from their digits. 1-1-3 becomes un-un-tri-ium, so element 113 was called ununtrium (Uut). Many older periodic tables still show Uut.
- Naming rights: once IUPAC credited RIKEN at the end of 2015, the team was invited to propose a name. Under IUPAC rules a new element can be named after a mythological concept, a mineral, a place or country, a property, or a scientist.
- The proposal: the team chose nihonium, from Nihon (日本), one of the two ways to say "Japan" in Japanese. The phrase is often translated as "land of the rising sun".
- Public review and approval: IUPAC published the proposal on 8 June 2016, together with moscovium, tennessine and oganesson. After a five-month comment period, the names were approved on 28 November 2016.
Nihonium was the first element to be discovered in an Asian country, and so the first named by a team from Asia. It joins other elements named after places or countries, such as germanium, polonium, francium and americium.
Is Element 113 Useful for Anything?
Nihonium has no practical uses. Only a few atoms exist at any time, and each decays within seconds, so it can't be used in products or technology. Its value is scientific. Experiments on nihonium test models of how heavy nuclei hold together, including the predicted "island of stability", and show how strong relativistic effects change the chemistry of very heavy atoms.
It also poses no hazard to the public. A single atom inside a detector, which decays almost immediately, can't produce a meaningful radiation dose. Only the accelerator facilities need radiation protection.
Frequently Asked Questions
What is element 113?
Element 113 is nihonium, symbol Nh. It is a synthetic, highly radioactive superheavy element in group 13 and period 7 of the periodic table. It does not occur in nature and has only ever been made a few atoms at a time in particle accelerators.
When was element 113 discovered?
RIKEN in Japan detected its first atom of element 113 on 23 July 2004, followed by further atoms on 2 April 2005 and 12 August 2012. IUPAC credited RIKEN with the discovery on 30 December 2015, and the name nihonium was approved on 28 November 2016.
Who found nihonium?
Nihonium was found by a team at the RIKEN Nishina Center for Accelerator-Based Science in Wako, Japan, led by Kosuke Morita. They fused zinc-70 ions with a bismuth-209 target. A Russian-American collaboration (JINR Dubna and Lawrence Livermore) also reported element 113 atoms in 2004, but IUPAC and IUPAP judged RIKEN's evidence to be the first that met the discovery criteria.
Why is element 113 called nihonium?
The name comes from Nihon, one of the Japanese names for Japan. Before it was named, element 113 was known by the placeholder name ununtrium (Uut). The RIKEN team's proposal of nihonium (Nh) was published by IUPAC for public review in June 2016 and formally approved on 28 November 2016.
What group is nihonium in?
Nihonium is in group 13 (the boron group), below boron, aluminium, gallium, indium and thallium. It sits in period 7 and the p-block, between copernicium (112) and flerovium (114).
Is element 113 found in nature?
No. Every known isotope of nihonium decays within seconds or less, so none survives in nature. It exists only for moments after being created in a laboratory.
Element 113 vs Mass Number 113
"Element 113" refers to the atomic number: 113 protons. Mass number 113 is a different thing. It labels isotopes of other elements, such as indium-113 and cadmium-113, whose nuclei contain 113 protons and neutrons combined. Nihonium's own isotopes have mass numbers between about 278 and 286. See atomic mass 113 for the details.