Nihonium

Nihonium is element 113 (Nh), located in period 7, group 13 and the p block. No macroscopic sample exists, so an ordinary room-temperature phase is not established experimentally. Its calculated electron configuration is [Rn] 5f14 6d10 7s2 7p1.

Atomic number113

Standard atomic weightNo standard atomic weight

Group13

Period7

Blockp

Electron configuration[Rn] 5f14 6d10 7s2 7p1

Electronic structure

What controls its chemistry

Nihonium is a superheavy synthetic element. Only very small numbers of atoms have been produced, so its chemistry is studied through individual decay events and specialised atom-at-a-time experiments rather than bulk samples.

Its position in group 13 and the p block provides a first prediction of its chemistry, but relativistic effects become increasingly important for the heaviest nuclei. Experimental results are therefore essential before extending lighter-group trends too confidently.

Chemical forms

Compounds, ions and materials

Bulk nihonium compounds cannot be prepared because only tiny numbers of short-lived atoms are produced. Chemical experiments, when possible, test adsorption, volatility or single-atom reactions and compare the results with lighter elements in the same group.

Physical behaviour

State and phase changes

No macroscopic sample has been produced, so ordinary bulk properties such as density, melting point and boiling point are not established experimentally. Published values for superheavy elements are generally theoretical predictions and should be labelled as such.

Occurrence and applications

Where nihonium is found and used

In practice, nihonium is encountered in scientific research.

In practice

Examples of real uses

Scientific research

Nihonium is produced, isolated or measured mainly to test atomic, nuclear and periodic trends rather than for bulk commercial use.

Periodic position

What its neighbours tell us

Nihonium is in period 7 and group 13. In the neighbourhood shown here, it lies between copernicium and flerovium in the same period; thallium is directly above it in the same group. These positions make it possible to compare atomic size, ionisation energy and bonding behaviour with nearby elements.

Reference data

Physical and atomic properties

Classificationunknown, probably transition metal

Phase at room temperatureNot established experimentally

Electron shells2 · 8 · 18 · 32 · 32 · 18 · 3

DensityNot established experimentally

Melting pointNot established experimentally

Boiling pointNot established experimentally

Pauling electronegativity—

First ionisation energy—

Electron affinity—

Values describe the element or neutral atom where applicable. Physical data can depend on allotrope, pressure and measurement conditions.

History

Discovery and identification

Nihonium is synthetic. It is produced in nuclear-reaction experiments and identified from the decay chains of the atoms created. The quantities involved are far below anything that could form a visible sample.

Isotopes and atomic weight

How isotope composition changes the numbers

Nihonium has no standard atomic weight. There is no characteristic terrestrial isotopic mixture from which a stable abundance-weighted average can be assigned.

Nihonium has no stable isotope. Its isotopes are radioactive, and their half-lives and decay modes become important whenever the element is measured, handled or used.

Safety

Handling and exposure

Nihonium is radioactive. Work with it requires radiological controls appropriate to the isotope, activity, radiation type and chemical form.