Nihonium's chemical category has not been confirmed by experiment, so it is listed with unclassified properties.

How many protons does nihonium have?

Nihonium has 113 protons. Its atomic number is 113, which is also the number of electrons in a neutral atom of nihonium.

What group and period is nihonium in?

Nihonium is in group 13 and period 7 of the periodic table, in the p-block.

What is the atomic mass of nihonium?

The atomic mass of nihonium is 286 u (unified atomic mass units).

Element 113

Nihonium (Nh)

Element with unclassified properties · Period 7 · Group 13 · p-block

Nihonium (Nh) is element 113 of the periodic table, an element with unclassified properties in period 7, group 13 (p-block) with an atomic mass of 286 and is a solid at standard conditions.

At a glance

Atomic number: 113
Symbol: Nh
Atomic mass: 286 u
Category: Unclassified properties
Period: 7
Group: 13
Block: p-block
Phase at STP: solid

Electron structure

Electron configuration: 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p6 5f14 6d10 7s2 7p1
Shorthand configuration: [Rn] 5f14 6d10 7s2 7p1
Electrons per shell: 2, 8, 18, 32, 32, 18, 3
Oxidation states: +3

Physical properties

Nihonium has only ever been produced in quantities too small to weigh or observe in bulk. The physical and atomic values below are theoretical predictions from periodic trends and relativistic calculations, not measurements.

Melting point: 700 K (426.85 °C) (predicted)
Boiling point: 1,400 K (1,126.85 °C) (predicted)
Density: 16 g/cm³ (predicted)
Phase: solid

Atomic properties

Covalent radius: 136 pm (predicted)
First ionization energy: 707 kJ/mol (predicted)
Electron affinity: 67 kJ/mol (predicted)

Notable isotopes

Notable isotopes of Nihonium: mass number, atomic mass, natural abundance, and stability.
Isotope	Mass	Abundance	Stability
Nh-286	286.18221	-	Half-life 9.5 seconds

Common uses

Scientific research only

Discovery

Year: 2003
Discovered by: RIKEN
Country: Japan

Frequently asked questions

Is nihonium a metal?: Nihonium's chemical category has not been confirmed by experiment, so it is listed with unclassified properties.
How many protons does nihonium have?: Nihonium has 113 protons. Its atomic number is 113, which is also the number of electrons in a neutral atom of nihonium.
What group and period is nihonium in?: Nihonium is in group 13 and period 7 of the periodic table, in the p-block.
What is the atomic mass of nihonium?: The atomic mass of nihonium is 286 u (unified atomic mass units).

Keep exploring

Nihonium's row is on the printable element property sheet, and its tile is on the periodic table wall chart - the same numbers as above, laid out for A4 or A3 paper.