Moscovium

group 15 · period 7 · p-block · unknown, probably post-transition metal

Identity

Name and symbol: Moscovium, Mc
Atomic number: 115 protons
Position: group 15 · period 7 · p-block · unknown, probably post-transition metal
CAS number: 54085-64-2

Atomic structure

Atomic mass: 289 u
Electron configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f¹⁴ 6d¹⁰ 7p³
[Rn] 7s² 7p³ 5f¹⁴ 6d¹⁰(predicted)
Electrons per shell: 2, 8, 18, 32, 32, 18, 5
Valence electrons: 5 outer shell

nuclide	half-life	decay
²⁹²Mc	5 s [Estimated]	α ?; SF ?
²⁹¹Mc	1 s [Estimated]	α ?; SF ?
²⁹⁰Mc	840 ms	α=100%
²⁸⁹Mc	410 ms	α=100%

no stable isotope; the longest-lived nuclides

Physical properties

State at room temperature: Expected to be a Solid
Melting point: 670 K (396.85 °C)
Boiling point: not in sources
Density: not in sources
Appearance: not in sources
Thermal conductivity: not in sources
Electrical resistivity: not in sources
Electrical conductivity: not in sources
Crystal structure: not in sources
Molar heat capacity: not in sources

Chemical properties

Oxidation states: 1, 3 (prediction)
Electronegativity: not in sources
Ionisation energy: not in sources
Electron affinity: not in sources
Atomic radius: not in sources
Ionic radius: not in sources

Reactivity: A group 15 transactinide whose only chemistry is a 2024 GSI adsorption experiment on single atoms: on silica it is less reactive than bismuth but more reactive than the closed-shell neighbours copernicium and flerovium.
with water: Not known; no experiment has been reported.
with oxygen, air: Not known; no experiment has been reported.
with acids: Not known; no experiment has been reported.
with halogens: Not known; no experiment has been reported.

Typical compounds: not in sources

Occurrence, production and use

Crustal abundance: Not Applicable
Oceanic abundance: Not Applicable

Occurrence and sources

synthetic only americium-243 bombarded with calcium-48 ions at Dubna

Extraction, production: not in sources

Uses: Since only a few atoms of moscovium have ever been produced, it currently has no uses outside of basic scientific research.

Safety, toxicity: not in sources

Discovery and name

Discovered by: Joint Institute for Nuclear Research and Lawrence Livermore National Laboratory
Discovered: 2003
First isolated: not in sources
Named by: not in sources
Origin of the name: After Moscow region

Moscovium does not occur naturally in the Earth’s crust. The name moscovium and the symbol Mc, are the accepted ones for element 115. The name is in recognition of the Moscow region and honors the ancient Russian land that is home to the Joint Institute for Nuclear Research (JIRN), where the discovery experiments were conducted using the Dubna gas filled recoil separator in combination with the heavy ion accelerator capabilities of the Flerov Laboratory of Nuclear Reactions.

48Ca and 243Am were bombarded together in a cyclotron during a series of experiments from 14 July to 10 August 2003 (Fig. IUPAC.115.1). In February 2004, the results from these experiments were released in a report that stated “ununpentium” had been synthesized. This initial name means “115” in the IUPAC systematic naming scheme, which combines Latin and Greek names to produce un-un-pentium for 115. Moscovium has no known isotopic applications aside from scientific research.

Conventions

Valence electrons are counted by the usual convention: the outer shell for s- and p-block elements, ns and (n-1)d for the d-block, ns, (n-1)d and (n-2)f for the f-block. Lanthanides and actinides are placed in the f-block with no group number. Electrical conductivity is the reciprocal of the printed resistivity. Ionic radii are Shannon effective radii, six-coordinate unless noted. Where a field reads “not in sources” the value was not found; it is a gap, not a zero. Regulatory limits are the published values and change often, so check the standard in force at your site and the numbers written into your own permit before you design to them.

Data

Element records, isotopes, radii and the descriptive text come from PubChem (NCBI), the Los Alamos National Laboratory periodic table, IUPAC CIAAW and the IAEA Atomic Mass Data Center. Appearance, thermal conductivity, electrical resistivity, crystal structure, discovery and the origin of each name come from Wikipedia and Periodic-Table-JSON, used under CC BY-SA 4.0. Hazard classifications come from the ECHA C&L inventory via PubChem. Ionic radii follow R. D. Shannon (1976). The water chapters cite their own sources at the foot of each entry, and are written to the level of Snoeyink and Jenkins, Stumm and Morgan, MWH's Water Treatment and Metcalf and Eddy.