Moscovium (Mc)

Moscovium is a synthetic, highly radioactive superheavy element in group 15. Only minute amounts are produced in particle accelerators; its known isotopes decay within seconds.

Atomic Number
115
Atomic Mass
289
Phase (STP)
Solid
Block
P
Electronegativity (Pauling)

Bohr Atomic Model

Protons
115
Neutrons
175
Electrons
115
Identity
Atomic Number115
SymbolMc
NameMoscovium
Group15
Period7
Position
Period7
Group Label15
Grid X15
Grid Y7
Physical Properties
Atomic Mass (u)289
Density (g/cm³)
Melting Point (K)null K null °C
Boiling Pointnull K null °C
Phase at STPSolid
CategoryPost-Transition Metals
Liquid Density (g/cm³)
Molar Volume (cm³/mol)
Emission Spectrum (nm)
Discovery
English NameMoscovium
English Pronunciationmoss-CO-vee-um
Latin Name
Latin Pronunciation
Year2010
DiscovererScientists from the Joint Institute for Nuclear Research in Dubna, Russia, the Lawrence Livermore National Laboratory in California, USA, and Oak Ridge National Laboratory in Tennessee, USA
CountryRussia; United States
CAS Number54085-64-2
CID Number
RTECS Number
Atomic Properties
Electron ShellK2 L8 M18 N32 O32 P18 Q5
Electron Configuration[Rn] 5f^1^46d^1^07s^27p^3
Oxidation States-1 +1 +3
Ion Charge
Ionization Potential (eV)
Electronegativity (Pauling)
Electron Affinity (kJ/mol)
Electrons115
Protons115
Neutrons175
Valence
BlockP
Atomic Radius (pm)
Covalent Radius (pm)162
van der Waals Radius (pm)
Thermodynamic Properties
PhaseSOLID
Heat of Fusion (kJ/mol)
Specific Heat (J/g·K)
Thermal Expansion (1/K)
Heat of Vaporization (kJ/mol)
Mechanical Properties
Brinell Hardness
Mohs Hardness
Vickers Hardness
Bulk Modulus (GPa)
Young's Modulus (GPa)
Shear Modulus (GPa)
Poisson Ratio
Sound Speed (m/s)
Refractive Index
Thermal Conductivity (W/m·K)
Electromagnetic Properties
Electrical Conductivity (S/m)
Electrical Type
Magnetic Type
Volume Magnetic Susceptibility
Mass Magnetic Susceptibility
Molar Magnetic Susceptibility
Resistivity (Ω·m)
Superconducting Point (K)
Crystal Properties
Structure
System
Space Group
a (Å)
b (Å)
c (Å)
α (°)
β (°)
γ (°)
Debye Temperature (K)
Nuclear Properties
RadioactiveNo
Half-lifeMost stable known isotope 290Mc: t₁/₂ ≈ 0.65 s
Lifetime
Neutron Cross-section (barn)
Safety Information
Health HazardRadioactive; emits alpha decay products
Reactivity Hazard
Specific HazardHandle only in specialized radiological facilities
Prevalence
Universe0
Sun0
Oceans0
Human Body0
Earth Crust0
Meteorites0


FAQs about Moscovium

Moscovium (Mc) is a superheavy, synthetic p-block element with atomic number 115. It belongs to Group 15 (the pnictogens: N, P, As, Sb, Bi) in period 7. It does not occur naturally and must be made atom-by-atom in particle accelerators.

Mc is created in fusion–evaporation reactions. A widely used route bombards americium with calcium-48; the hot compound nucleus cools by emitting a few neutrons to yield Mc isotopes:

\(^{243}\mathrm{Am}(^{48}\mathrm{Ca},\,3n)\,^{288}\mathrm{Mc}\)

\(^{243}\mathrm{Am}(^{48}\mathrm{Ca},\,4n)\,^{287}\mathrm{Mc}\)

Newly formed atoms recoil into a separator and implant into position-sensitive detectors. Identification relies on time-correlated decay chains—mostly \(\alpha\) decays (and sometimes spontaneous fission)—with characteristic energies and lifetimes:

\(^{A}_{115}\mathrm{Mc} \;\xrightarrow{\alpha}\; ^{A-4}_{113}\mathrm{Nh} \;\xrightarrow{\alpha}\; ^{A-8}_{111}\mathrm{Rg} \;\to\; \cdots\)

Observed isotopes lie near \(A\approx 287\text{–}290\). Half-lives are typically hundreds of milliseconds to a few seconds, long enough to register decay chains but too short for bulk measurements or conventional wet-chemistry experiments.

By Group-15 analogy (and allowing for strong relativistic effects), +1 and +3 are expected to be the most accessible states; +5 is likely less stable than in lighter pnictides. The dominance of +1/+3 is linked to stabilization of the 7s pair and splitting of the 7p subshell.

A commonly cited ground-state configuration is [Rn] 5f14 6d10 7s2 7p3. Strong relativistic stabilization of 7s and spin–orbit splitting of 7p (\(7p_{1/2}\) vs. \(7p_{3/2}\)) help explain the expected preference for the +1 and +3 oxidation states.

Because only a few atoms are produced and they decay quickly, direct aqueous chemistry has not been established. Theory and single-atom gas-phase approaches suggest possible monovalent halides (e.g., McCl) and trivalent species (e.g., McCl3) under highly controlled, chlorinating conditions, but definitive series remain an active research topic.

Experiments yield atom-scale quantities with second-scale lifetimes, preventing preparation of macroscopic samples. Thus, density, melting point, crystal structure, and color are mainly predictions from relativistic quantum calculations and periodic trends.

Yes. Mc is a radiotoxic heavy element. Even though experiments handle only a few atoms at a time, research requires hot-cell or glove-box techniques, high-vacuum separators, shielding, HEPA-filtered ventilation, dosimetry, and compliant radioactive-waste procedures.

Production (stylized fusion–evaporation) and subsequent \(\alpha\) decay:

\(^{243}\mathrm{Am}(^{48}\mathrm{Ca},\,3n)\,^{288}\mathrm{Mc}\;\xrightarrow{\alpha}\; ^{284}\mathrm{Nh} + \alpha\)

Chains typically continue via successive \(\alpha\) emissions and may end in spontaneous fission of a daughter nuclide.