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Mc

Moscovium

properties predicted

Moscovium (Mc) is a post-transition metal with atomic number 115. It has no stable isotope and no characteristic isotopic composition on Earth, so it has no standard atomic weight. CIAAW lists moscovium-288, moscovium-289 and moscovium-290 as its longest-lived isotopes, and the mass number used here is 290. Its electron configuration is predicted to be [Rn] 5f14 6d10 7s2 7p3, which gives it 5 valence electrons.

Moscovium key data

Symbol Mc
Atomic number 115
Mass number (one of its longest-lived isotopes) 290
Protons 115
Neutrons (moscovium-290) 175
Electrons (neutral atom) 115
Valence electrons 5
Category Post-transition metal
Period 7
Group 15
Block p-block
Noble gas notation [Rn] 5f14 6d10 7s2 7p3
Full electron configuration 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

Mass number: IUPAC CIAAW radioactive elements, from NUBASE2020.

The values are facts and free to use; this page’s selection and presentation are © 2026 ScienceQuest.

Properties of moscovium

From PubChem, the US National Institutes of Health. Public domain. Most properties of this element are predicted, because only a few atoms have ever been made.

Predicted state at room temperature Solid
Predicted oxidation states +3, +1
Discovered 2003

Moscovium electron configuration

The full electron configuration of moscovium is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f14 6s2 6p6 6d10 7s2 7p3. With the noble-gas core collapsed it is [Rn] 5f14 6d10 7s2 7p3, and the outermost subshell is 7p3.

Bohr model of moscovium (Mc): a nucleus and seven shells holding 2, 8, 18, 32, 32, 18 and 5 electrons from the inside out.
Bohr model of moscovium (Mc). Image © ScienceQuest, CC BY 4.0: free to reuse with credit to ScienceQuest and a link to this page, as the image licence explains.
Orbital box diagram of moscovium (Mc), [Rn] 5f14 6d10 7s2 7p3, with the radon core drawn as one bar: one box per orbital, filled by Hund’s rule, showing three unpaired electrons, in 7p.
Orbital diagram of moscovium (Mc). Image © ScienceQuest, CC BY 4.0: free to reuse with credit to ScienceQuest and a link to this page, as the image licence explains.

Why group and block follow from this is set out in how the periodic table maps electron configuration, and the electron configuration of every element is listed on one page.

Mass of one moscovium atom

A molar mass is grams per mole, so dividing by the Avogadro constant gives the mass of a single atom, or for an element with more than one natural isotope the average mass of its atoms, and the reciprocal gives how many atoms sit in a gram.

Mass of one atom

  1. one atom = 290 / (6.02214076 × 10²³)
  2. = 4.8156 × 10⁻²² g

Atoms in one gram

  1. atoms per gram = 6.02214076 × 10²³ / 290
  2. = 2.0766 × 10²¹ atoms

Moscovium has no standard atomic weight, because it has neither a stable isotope nor a characteristic isotopic composition on Earth. The figure used above is the mass number of moscovium-290, so treat these as nominal.

Moscovium on the periodic table

Moscovium is in period 7, group 15, in the p-block.

The other elements of group 15 are nitrogen, phosphorus, arsenic, antimony and bismuth.

The rest of period 7

Work with moscovium