Nihonium (Nh)

Nihonium is the first element discovered in Asia, and the effort behind it is worth stating plainly: RIKEN fired zinc ions at a bismuth target more or less continuously for nine years, roughly 400 trillion collisions, and got three atoms. The first arrived in July 2004, the second in April 2005, and the third not until August 2012 — the team kept the beam running for seven years waiting for it, because two atoms were not enough to claim the element. The name comes from Nihon, one of the Japanese words for Japan.

Properties

Atomic number

113

Symbol

Nh

Mass number of most stable isotope

[286]

Category

Post-transition metal

Group

13

Period

7

Block

p-block

Electron configuration

[Rn] 7s² 5f¹⁴ 6d¹⁰ 7p¹

Electrons per shell

2, 8, 18, 32, 32, 18, 3

Oxidation states

+1, +3

Discovered

2004 by Kosuke Morita and colleagues at RIKEN, Japan

Electron configuration

Full

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f¹⁴ 6d¹⁰ 7p¹

Noble gas shorthand

[Rn] 7s² 5f¹⁴ 6d¹⁰ 7p¹

Shells

K: 2 · L: 8 · M: 18 · N: 32 · O: 32 · P: 18 · Q: 3

What it is used for

• Research only; no application outside the laboratory

Hazards

• Intensely radioactive; exists only as individual atoms in an accelerator

Melting point, boiling point, density and electronegativity are omitted: nothing here has been measured, and every published figure is an extrapolation. The electron configuration is calculated. The mass given is the mass number of nihonium-286, the longest-lived at roughly 10 seconds.

Several physical properties are not listed for nihonium because no bulk sample has ever existed. Only a handful of atoms have been produced, often with half-lives measured in seconds, so published melting points and densities for elements in this range are calculations rather than measurements. They are omitted rather than presented as observed values.

Neighbours in the table

Group 13

Elements in the same group share their outer electron count, which is why they behave similarly in reactions. Nihonium sits in group 13 with boron, aluminum, gallium, indium, thallium.