What Element Is 113 on the Periodic Table?
Last reviewed on 1 October 2026.
Element 113 on the periodic table is nihonium, symbol Nh. It sits in group 13 (the boron group), period 7 and the p-block, directly below thallium (Tl, 81) and between copernicium (Cn, 112) and flerovium (Fl, 114). Nihonium is a synthetic, radioactive superheavy element. It was first made in Japan in 2004 and officially named in 2016.
Element 113 Periodic Table Entry
| Name | Nihonium |
| Symbol | Nh (formerly Uut, ununtrium) |
| Atomic number | 113 |
| Atomic weight | [286], the mass number of its longest-lived known isotope (square brackets mean there's no stable isotope) |
| Group | 13 (boron group; IIIA in the older US system) |
| Period | 7 |
| Block | p-block |
| Electron configuration | [Rn] 5f14 6d10 7s2 7p1 (predicted) |
| Expected category | Post-transition metal (predicted) |
| Occurrence | Synthetic only |
Where to Find 113 on the Table
Go to the bottom row of the main table (period 7) and count across. After the actinides comes the run of superheavy transactinides from rutherfordium (104) to copernicium (112). The very next box, at the top of the p-block, is element 113. The column above it reads, from top to bottom:
| Group 13 element | Symbol | Atomic number | Period | Type |
|---|---|---|---|---|
| Boron | B | 5 | 2 | Metalloid |
| Aluminium | Al | 13 | 3 | Metal |
| Gallium | Ga | 31 | 4 | Metal |
| Indium | In | 49 | 5 | Metal |
| Thallium | Tl | 81 | 6 | Metal |
| Nihonium | Nh | 113 | 7 | Metal (predicted) |
Its period 7 neighbours are other superheavy elements that received their names between 2010 and 2016:
- 112, copernicium (Cn): group 12, to the left
- 113, nihonium (Nh): group 13
- 114, flerovium (Fl): group 14, to the right
- 115, moscovium (Mc); 116, livermorium (Lv); 117, tennessine (Ts); 118, oganesson (Og), which completes period 7
What Its Position Tells Us
Elements in the same group have the same number of valence electrons, so their place in the table hints at their chemistry:
- Three valence electrons (7s2 7p1). Lighter group 13 elements usually lose all three and form +3 compounds, such as Al2O3.
- The inert-pair effect. Going down the group, the s-pair becomes reluctant to react. Thallium already prefers +1 over +3. Nihonium is predicted to favour +1 even more strongly.
- Relativistic effects. In a nucleus with 113 protons, the inner electrons move fast enough that relativity measurably contracts and stabilises the 7s and 7p1/2 orbitals. This is why nihonium's chemistry is expected to drift from simple group trends.
Very few chemistry experiments on nihonium have been possible, so these expectations rest mainly on theory. For isotopes, half-lives and predicted physical properties, see nihonium properties and isotopes.
How Element 113 Got Its Place on the Table
Element 113 was first made by Kosuke Morita's team at RIKEN on 23 July 2004, by fusing zinc-70 with bismuth-209. IUPAC credited the discovery to RIKEN on 30 December 2015 and approved the name nihonium, after Nihon (Japan), on 28 November 2016. Periodic tables printed before then show it as ununtrium (Uut). The full timeline, the competing Dubna–Livermore claim and the naming story are on our main page: element 113 (nihonium): discovery and name history.
Frequently Asked Questions
What is the periodic table element for 113?
The element with atomic number 113 is nihonium, symbol Nh. It is in group 13, period 7, directly below thallium (Tl) and between copernicium (Cn, 112) and flerovium (Fl, 114).
What is the symbol for element 113?
The symbol is Nh, for nihonium. Older periodic tables printed before 2016 may show the temporary symbol Uut, for ununtrium.
What is the electron configuration of element 113?
The predicted ground-state electron configuration of nihonium is [Rn] 5f14 6d10 7s2 7p1. Like the other group 13 elements it has three valence electrons, two in the s subshell and one in the p subshell.
Is element 113 a metal?
Nihonium is expected to be a post-transition metal, like thallium above it, but this is a prediction. Too few atoms have been made to observe the bulk element.