Atomic number 115 · Post-transition metal
Moscovium Mc
Moscovium is a superheavy element named after the Moscow region of Russia. It sits in group 15 below nitrogen, phosphorus, arsenic, antimony and bismuth. First made by a Russian–American team in 2003, its decay chain also revealed element 113 and the long-lived dubnium-268.
Key properties
| Atomic number | 115 |
|---|---|
| Atomic weight | [290] (No stable isotope; mass number of a representative isotope in brackets) |
| Category | Post-transition metal |
| Group | 15 |
| Period | 7 |
| Block | p |
| State (25 °C, 1 atm) | Solid (Predicted) |
| Melting point | — |
| Boiling point | — |
| Density | — |
| Electronegativity (Pauling) | — |
| Atomic radius (van der Waals) | — |
| First ionization energy | — |
| Electron affinity | — |
| Oxidation states | 3, 1 |
| Discovered | 2003 |
Electron configuration
- Condensed
- [Rn]7s2 7p3 5f14 6d10
- Full
- 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f14 6s2 6p6 6d10 7s2 7p3
- Electrons per shell
- 2 · 8 · 18 · 32 · 32 · 18 · 5
Orbital diagram
Electron configurations of some superheavy elements (beyond 103) are theoretical predictions.
Position in the table
Discovery
In August 2003 a collaboration between the Joint Institute for Nuclear Research in Dubna and Lawrence Livermore National Laboratory bombarded americium-243 with calcium-48 ions and produced four atoms of element 115, publishing the results in February 2004. Each atom alpha-decayed through element 113 down to dubnium-268. The team strengthened the case by chemically separating the dubnium at the end of the chain to confirm its atomic number.
Further confirmations followed, including a 2013 repeat of the experiment by Lund University and GSI. In December 2015 IUPAC credited the Dubna–Livermore–Oak Ridge collaboration, and the name was approved on 28 November 2016.
Origin of the name
The name comes from the Moscow Oblast, the region around Moscow in which Dubna lies. The symbol is Mc. Since the town's name was already taken by element 105, dubnium, the broader region was chosen this time.
Main uses
- Basic research: It has no uses outside science.
- A gateway to other nuclei: Moscovium's decay chains produce nihonium and dubnium-268, letting researchers study several elements from the same experiments. It is predicted to resemble bismuth, but chemical studies are at an early stage.
Isotopes
There are no stable isotopes. The longest-lived, moscovium-290, has a half-life of about 0.65 seconds. Moscovium-288, the first isotope made, lasts about 0.2 seconds and leaves dubnium-268, with its half-life of around 16 hours, at the end of its decay chain.
In everyday life
It does not exist in nature; only a few atoms at a time are made in accelerators and they decay almost immediately, so it has no connection with daily life or health.
Good to know
- The first experiments produced four atoms of moscovium.
- Chemically isolating the dubnium-268 at the end of the decay chain helped confirm the discovery.
- The name honours the Moscow region rather than a city.
Same group (15)
Data sources · Properties: PubChem Periodic Table (US NIH/NLM public data) · Atomic weights: CIAAW 2024 abridged standard atomic weights · Names: Wikidata (CC0); Korean names follow the Korean Chemical Society. Retrieved 2026-09-23.