Nihonium (Nh)
“First glimpsed at Japan’s RIKEN laboratory in 2004 and named in 2016 for “Nihon” — Japan itself — nihonium is the first element ever discovered and named in East Asia.”
How its electrons are arranged
Computed from the aufbau principle, with known real-world exceptions applied automatically.
Characteristics
- A purely artificial superheavy element — every nihonium atom ever made was assembled in an accelerator and decayed away within seconds.
- It heads Group 13 below thallium, and relativistic calculations tip its chemistry toward the +1 oxidation state, echoing thallium’s famous preference.
- Its longest-lived isotopes, such as Nh-286 arriving in moscovium decay chains, persist for some twenty seconds — a rarity among superheavies.
- The single 7p electron ending its configuration makes nihonium the periodic-table doorstep between the superheavy metals and the unknown 8th row.
Nihonium has existed only as scattered single atoms that fade within seconds. Theorists predict a heavy cousin of thallium: a dense, silvery post-transition metal whose single outer 7p electron — pulled inward by relativistic effects — makes the +1 oxidation state its most stable costume, much as thallium prefers +1 over +3.
Where you meet it
✦ Uses
- Nihonium’s decay chains serve as reference ladders: spotting them confirms that moscovium and tennessine atoms really formed, since those heavier elements announce themselves by decaying through nihonium.
- Its seconds-long isotopes give nuclear physicists measurable footholds for testing shell-model predictions about the edge of the chart of nuclides.
- RIKEN’s nine-year hunt for element 113 became a case study in patient accelerator science, shaping how laboratories budget long-shot discovery programmes.
◍ Everyday examples
- Japanese schoolbooks can now point at one box and say “our element” — 113 is the first discovered on Japanese soil, and its name says so.
- In decay-chain diagrams of the 2010s Dubna experiments, nihonium isotopes appear as the identifiable middle rungs between moscovium and roentgenium.
- Before 2016, exam charts carried the awkward placeholder “ununtrium” — students who memorised it had to relearn Nh after the naming.
History & name
In February 2004 Kosuke Morita’s team at RIKEN near Tokyo fused zinc-70 with bismuth-209 and recorded a decay chain from a single atom of nihonium-278 — the first element ever discovered in Japan. Two more chains followed in 2005 and 2007, and after a respectful rivalry with the Dubna–Livermore collaboration, whose moscovium decay chains also produced atoms of element 113, IUPAC in 2015 awarded the discovery to RIKEN. In 2016 the element became nihonium — from “Nihon”, a poetic name for Japan — making it the first element named in an East Asian language and only the second, after americium, named for a place its discoverers called home. Morita had asked the public for name ideas and received thousands; the final choice honoured the country whose basic science budget kept a nine-year hunt alive.