Nihonium
Transition metal (predicted) · Period 7 · Group 13 · p-block
Japan's element, confirmed from three atoms in nine years
- Atomic mass
- 286 u
- State at 25 °C
- Solid
- Electronegativity
- —
- Melting point
- 426.9 °Cpredicted
- Boiling point
- 1,156.9 °Cpredicted
- Configuration
- *[Rn] 5f14 6d10 7s2 7p1
Nucleus drawn at reduced count for clarity. Drag to rotate.
Nihonium, explained
Video lesson in production
Bhavya’s explainer for this element will play here.
Overview
Nihonium is the first element of the 7p block, sitting in group 13 under boron, aluminium, gallium, indium and thallium. Its single outer p electron occupies a 7p1/2 orbital that relativistic spin-orbit splitting pulls down in energy and holds tightly. As a result nihonium is predicted to be less reactive than thallium, to favor the +1 oxidation state, and to have a higher ionization energy than its lighter neighbor.
Experimental chemistry on nihonium has only just begun, using the few atoms produced in hot-fusion reactions with calcium-48, and its properties remain mostly predicted. The longest-lived known isotope, nihonium-286, has a half-life of about 10 seconds. Nihonium also sits near the region where the predicted island of stability begins, so mapping its isotopes helps test models of how shell effects stabilize the heaviest nuclei.
Discovery
Kosuke Morita's team at RIKEN near Tokyo bombarded bismuth-209 with zinc-70 for years, detecting single atoms of nihonium-278 in 2004, 2005 and 2012. A Dubna-Livermore team had reported nihonium in 2004 as a decay product of moscovium. IUPAC credited RIKEN in December 2015, and the name, from Nihon, a Japanese name for Japan, was approved in November 2016. It was the first element discovered in Asia.
- Where it’s found
- Nihonium does not occur in nature; it is made in accelerators or as a decay product of moscovium.
- What it’s used for
- Relativistic effects research
- Testing group 13 predictions
- Island of stability studies
- Nuclear structure research
- In living things
- Nihonium has no biological role; it is radioactive and has only ever existed as individual atoms.
- Safety
- Radioactive and made only a few atoms ever; it decays within seconds or less.
How it compares
Where Nihonium sits among all 118 elements on the trends that shape the table.
- ElectronegativityNo data
Not measured for this element
- Ionization energyNo data
Not measured for this element
- Atomic radiusNo data
Not measured for this element
- Electron affinity66.6kJ/mol
#41 of 109 elements with data · predicted
- Density16g/cm³
#19 of 114 elements with data · predicted
- Melting point700K
#74 of 110 elements with data · predicted
- Density
- 16 g/cm³
- Atomic radius
- —
- Covalent radius
- —
- Molar heat
- —
- Appearance
- —
- Discovered by
- RIKEN
Inside the atom
113 electrons arranged in 7 shells: 2 · 8 · 18 · 32 · 32 · 18 · 3.
Orbital diagram
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d10 7p1 · shorthand *[Rn] 5f14 6d10 7s2 7p1
- 1s2
- 2s2
- 2p6
- 3s2
- 3p6
- 4s2
- 3d10
- 4p6
- 5s2
- 4d10
- 5p6
- 6s2
- 4f14
- 5d10
- 6p6
- 7s2
- 5f14
- 6d10
- 7p1
Each box is an orbital holding up to two electrons of opposite spin. Highlighted subshells hold the valence electrons that decide how Nihonium bonds.
Signature reactions
How the first atoms were made, and how they fall apart.
Nuclear · Cold fusion
RIKEN cold-fusion synthesis
Zinc-70 fuses with bismuth-209 and the compound nucleus emits one neutron. The cross-section was only about 20 femtobarns, so three atoms required hundreds of days of beam time.
Conditions: zinc-70 beam on bismuth-209, RIKEN linear accelerator, 2003-2012
Nuclear · Alpha decay
Alpha decay of nihonium-278
Nihonium-278 starts a chain of alpha decays through roentgenium, meitnerium and bohrium. The 2012 atom's chain of six alpha decays reached known nuclides and clinched RIKEN's claim.
Conditions: spontaneous, half-life about 2 milliseconds
Nuclear · Alpha decay
Formation from moscovium
Moscovium-288, made at Dubna from americium-243 and calcium-48, decays to nihonium-284. This is how the Dubna-Livermore team first reported element 113 in 2004.
Conditions: spontaneous, half-life about 0.2 seconds
Where you’ll meet it
Japan
Nihon, one of the Japanese names for Japan, gives element 113 its name.
Photo: Wikimedia Commons
Mount Fuji
Japan's iconic peak stands for the country that discovered and named element 113.
Photo: Wikimedia Commons
Kōsuke Morita
Morita led the RIKEN team that spent nearly a decade catching three atoms of nihonium.
Photo: Wikimedia Commons
Thallium
Thallium, directly above nihonium in group 13, is the reference for its predicted +1 chemistry.
Photo: Wikimedia Commons
Research
No research on Nihonium yet
When Bhavya publishes a project that studies Nihonium, it will be linked here.