Moscovium at a glance
- Atomic number
- 115
- Symbol
- Mc
- Atomic mass
- 290 u
- Category
- Post-transition metal
- Group / period
- 15 / 7
- Electron configuration
- [Rn] 5f 14 6d 10 7s 2 7p 3
- State at 25 °C
- Unknown
- Melting point
- n/a
- Boiling point
- n/a
- Density
- 13.5 g/cm³
- Electronegativity
- n/a
- 1st ionization energy
- 538 kJ/mol
- Oxidation states
- n/a
- Discovered
- 2003
Atomic structure
A neutral moscovium atom has 115 protons and 115 electrons, and its most common isotope carries about 175 neutrons. One atom weighs about 4.82 × 10⁻²⁵ kg, so a mole of moscovium (6.022 × 10²³ atoms) weighs 290 g. That nucleus holds 1.52 neutrons for every proton, typical of heavy nuclei, which need extra neutrons to hold together against the protons' repulsion. The electrons fill 7 shells (K 2, L 8, M 18, N 32, O 32, P 18, Q 5), which gives the configuration [Rn] 5f 14 6d 10 7s 2 7p 3. With 5 electrons in its outer shell, it tends to gain or share electrons to complete its outer shell. Every isotope is radioactive and short-lived; only a handful of atoms have ever been made, one at a time.
Physical properties
So little moscovium has ever existed at once that its melting point, boiling point and even its state at room temperature are unknown. Its density is 13.5 g/cm³ (predicted), 13.5 times as dense as water.
Chemical behaviour
It has no measured electronegativity. Pulling off its outermost electron takes 538 kJ/mol (predicted), less than Bismuth above it (703 kJ/mol). Group 15 also holds Nitrogen, Phosphorus, Arsenic, Antimony and Bismuth, which share its outer-shell pattern. Its Lewis symbol is Mc surrounded by 5 dots. Handle with care: as a pure element it is radioactive.
Where it comes from
It does not occur in nature in useful amounts; it is made in nuclear reactors or particle accelerators. It was first made at Dubna, with Lawrence Livermore by fusing americium-243 with calcium-48. Its longest-lived known isotope is Mc-290, under a second. It was first identified in 2003, making it the 116th element to be discovered (counting the 11 known since antiquity together).