Nh · Element 113 · Post-transition metal
The first element discovered and named by an Asian research team.
Structure
Not a diagram of dots on rings — a Monte-Carlo sample of the actual probability density |ψ|² for each occupied subshell. Drag to rotate. Blue and violet mark opposite signs of the wavefunction, which is what makes bonding possible.
Measured values
Every bar shows where nihonium sits among all 118 elements for that property.
Sources: IUPAC 2021 standard atomic weights · CRC Handbook of Chemistry and Physics · NIST. Values marked ~ are predicted rather than measured.
Same element, different neutrons
All nihonium atoms have the same number of protons, 113, and differ only in their number of neutrons: those variants are its isotopes. None of them is stable. The longest-lived known isotope, Nh-286, has 173 neutrons and a half-life of 9.5 sec.
| ISOTOPE | Neutrons | Natural Abundance | Half-life | Decay Mode |
|---|---|---|---|---|
| Nh-282 | 169 | — | ~0.07 sec | α |
| Nh-284 | 171 | — | 0.97 sec | α |
| Nh-285 | 172 | — | 0.93 sec | α, SF |
| Nh-286 longest-lived | 173 | — | 9.5 sec | α |
| Nh-290 | 177 | — | ~2 sec | α, SF |
Periodic tables list 284 for nihonium: the mass number of one long-lived isotope, not an average, so mass minus atomic number gives 171, the neutron count of Nh-284.
Decay modes
~ marks a half-life whose published uncertainty is larger than the value itself.
Data: IAEA Nuclear Data Section, LiveChart of Nuclides, ground-state evaluations, retrieved October 10, 2026. Abundance is the share of atoms in the natural element; a dash means the isotope has no standard natural abundance.
Size, to scale
Radius 247 pm — that is 0.247 nm, so about 2.02 million of them side by side would span a millimetre.
Thermal range
Nihonium is liquid over a 700 K window, from 700 K to 1400 K.
The story
The first element discovered and named by an Asian research team.
Historic Achievement: Nihonium became Japan's first discovered chemical element, representing a monumental achievement for Japanese science and earning recognition as one of the most significant scientific discoveries of the 21st century.
RIKEN Leadership: The discovery team, led by Kosuke Morita at RIKEN's Nishina Center for Accelerator-Based Science, spent nearly a decade perfecting the synthesis techniques required to create this superheavy element. Their persistence through years of failed attempts exemplifies scientific dedication.
Breakthrough Experiments: Between 2004 and 2012, the team successfully created three nihonium atoms by bombarding bismuth-209 targets with zinc-70 ions in their linear accelerator. Each successful synthesis required months of continuous operation and precise calibration of experimental conditions.
International Recognition: The International Union of Pure and Applied Chemistry (IUPAC) officially recognized RIKEN's discovery in 2015, granting Japan the honor of naming element 113. The name "nihonium" derives from "Nihon," the Japanese word for Japan.
Technological Innovation: The discovery required developing new detection systems capable of identifying single atoms among billions of background particles. These innovations advanced nuclear physics instrumentation and data analysis techniques worldwide.
Global Scientific Impact: Nihonium's discovery validated theoretical predictions about superheavy element synthesis and opened new avenues for exploring the periodic table's limits. The achievement inspired increased international collaboration in superheavy element research.
Cultural Significance: Beyond scientific importance, nihonium represents Japan's contribution to fundamental human knowledge, inspiring pride in Japanese scientific capabilities and motivating future generations of researchers.
Applications
Nuclear Physics Research: Nihonium serves as a crucial stepping stone in understanding superheavy element synthesis and decay patterns. It was first made by bombarding bismuth-209 targets with zinc-70 ions, and it also forms in the decay of moscovium made from americium-243 and calcium-48, providing insights into nuclear reaction mechanisms at very high energies.
Island of Stability Studies: As element 113, nihonium occupies a strategic position approaching the theorized "island of stability" where superheavy elements might exist for longer periods. Research focuses on determining if nihonium exhibits enhanced stability compared to neighboring elements, potentially validating theoretical predictions about nuclear shell closures.
Fundamental Chemistry Investigations: Despite its short half-life, nihonium research contributes to understanding how relativistic effects influence chemical bonding in superheavy elements. Theoretical calculations suggest nihonium might behave similarly to thallium, but with significant deviations due to relativistic electron orbital contractions.
Advanced Detection Technology: Creating nihonium requires advanced particle detection systems and sophisticated data analysis techniques. These technological developments advance our capabilities in nuclear instrumentation, benefiting fields from medical imaging to materials science.
International Scientific Collaboration: Nihonium research exemplifies global scientific cooperation, with teams from RIKEN (Japan), GSI (Germany), and other institutions sharing knowledge and resources to push the boundaries of element synthesis.
Educational Impact: As Japan's first discovered element, nihonium inspires new generations of scientists and demonstrates how persistent research can achieve seemingly impossible goals, motivating continued exploration of the unknown.
Particle Accelerator Experiments: Nihonium exists only in highly specialized research facilities equipped with linear accelerators and ion beam systems. These experiments require months of continuous bombardment to produce just a few atoms, making each creation a significant scientific achievement.
Nuclear Decay Studies: Scientists use nihonium to study alpha decay chains and fission fragments, providing data about nuclear stability and the forces that hold atomic nuclei together. Each nihonium atom that decays provides valuable information about superheavy element behavior.
Theoretical Model Validation: Nihonium serves as a testing ground for quantum mechanical models of atomic structure, particularly theories about how electron orbitals behave under very high nuclear charges and relativistic conditions.
Advanced Instrumentation Development: Creating and detecting nihonium drives innovation in particle detection technology, timing systems, and data acquisition methods that benefit broader scientific research.
International Research Coordination: Nihonium experiments require coordination between multiple research institutions, fostering collaboration and knowledge sharing in the global scientific community.
Future Applications Potential: While currently limited to research, understanding nihonium's properties contributes to the long-term goal of discovering stable superheavy elements that might have practical applications in advanced technologies.
Where it comes from
0 mg/kg of Earth's crust · more abundant than 0% of elements
No Natural Existence: Nihonium has never been found in nature. Its atomic nucleus contains 113 protons, making it far too unstable to survive in nature.
Artificial Creation Only: Every known nihonium atom has been created artificially in particle accelerators through nuclear fusion reactions. The process involves accelerating zinc-70 ions to extremely high energies and directing them at bismuth-209 targets, a reaction so slow that RIKEN detected only three atoms in nine years.
Cosmic Absence: It is an open question whether the r-process in neutron star mergers briefly makes nihonium nuclei; none could survive. The element's short half-life means any nihonium formed would decay before detection.
Laboratory-Exclusive Existence: RIKEN's linear accelerator in Japan made the atoms that established the discovery, while many more nihonium atoms have come from moscovium decay chains at JINR in Dubna. Its isotopes last from about a millisecond to about ten seconds before undergoing alpha decay, making its study extremely challenging.
Nuclear Instability: Nihonium's synthetic nature stems from the fundamental instability of heavy atomic nuclei. As proton number increases, the electromagnetic repulsion between protons overwhelms the strong nuclear force that holds the nucleus together.
Future Synthesis Potential: Advanced particle accelerator technologies might eventually enable more efficient nihonium production, but the element will always remain synthetic due to its inherent nuclear instability.
Handling
Nihonium is radioactive. It has no stable isotope — every nucleus decays. Handling requires appropriate shielding and licensing.
Atom-by-Atom Production: Nihonium is made only in heavy-ion accelerators. Atoms have only ever been made one at a time, and no weighable amount has ever existed.
Half-Lives: Its isotopes decay mainly by alpha emission, with half-lives from about 1.4 milliseconds (nihonium-278) to about 10 seconds (nihonium-286).
No Meaningful Dose: Alpha particles cannot penetrate the outer layer of skin and could harm tissue only from inside the body, and atoms made one at a time are far too few to deliver any meaningful dose.
Where the Hazards Are: The hazards in this research come from the experiment, not the element: the accelerator beam, radioactive targets and activated equipment, and the waste these produce, which is managed as radioactive waste under national radiation protection rules.
Worker Protection: Staff follow the standard occupational radiation rules: annual dose limits, personal dose monitoring and keeping doses as low as reasonably achievable. Workers under 18 face much lower dose limits than adults: one tenth of the adult limits under US Nuclear Regulatory Commission rules (10 CFR 20.1207), and 1 mSv a year at US Department of Energy laboratories (10 CFR 835.207). A worker who declares a pregnancy is limited to 5 mSv to the fetus over the whole pregnancy (10 CFR 20.1208 and 835.206).
Quick answers
Nihonium (symbol Nh) is element 113 on the periodic table, a post-transition metal in period 7, group 13. The first element discovered and named by an Asian research team. At room temperature it is expected to be a solid, and it is radioactive.
[Rn] 5f¹⁴ 6d¹⁰ 7s² 7p¹, giving 7 occupied shells with the distribution 2, 8, 18, 32, 32, 18, 3. Its outer shell holds 3 electrons, which is what sets its bonding behaviour.No sample of nihonium has ever been condensed, so both figures are calculated rather than measured: it is predicted to melt at 700 K (426.9 °C) and boil at 1400 K (1126.9 °C).
Nihonium has no stable isotope, so it has no standard atomic weight. The figure quoted, 284, is the mass number of Nh-284, the isotope periodic tables usually list; the longest-lived one in the IAEA data is Nh-286.
Nihonium has no stable isotope. Its longest-lived known isotope, Nh-286, has 173 neutrons (mass number 286 minus atomic number 113) and a half-life of 9.5 sec. Periodic tables list 284 for nihonium, the mass number of one long-lived isotope, so mass minus atomic number gives 171, the neutron count of Nh-284.
Nihonium is predicted to have a density of about 16 g/cm³, though no sample large enough to weigh has ever been made. Water is 1.0 g/cm³ for comparison.
Nihonium was discovered in 2004 by RIKEN, Japan. Origin of the name: Nihon, "Japan".
Nihonium does not occur naturally on Earth in any meaningful quantity — it is made in a reactor or an accelerator.
Yes. Nihonium has no stable isotope — every one of its nuclei decays. It does not occur in usable quantities in nature and must be synthesised.