Moscovium Facts: Element 115

Moscovium is a radioactive synthetic element that is atomic number 115 with element symbol Mc. Moscovium was officially added to the periodic table on November 28th in 2016. Prior to this, it was called by its placeholder name, ununpentium.

Moscovium Facts

Although element 115 received its official name and symbol in 2016, it was originally synthesized in 2003 by a team of Russian and American scientists working together at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia. The team was headed by Russian physicist Yuri Oganessian. The first atoms were produced by bombarding americium-243 with calcium-48 ions to form four atoms of moscovium (Mc-288 plus 3 neutrons, which decayed into Nh-284, and Mc-287 plus 4 neutrons, which decayed into Nh-283).

The decay of the first few atoms of moscovium simultaneously led to the discovery of the element nihonium.

Discovery of a new element requires verification, so the research team also produced moscovium and nihonium following the decay scheme of dubnium-268. This decay scheme was not recognized as exclusive to these two elements, so additional experiments using the element tennesine were conducted and earlier experiments were replicated. The discovery was finally recognized in December 2015.

As of 2017, about 100 atoms of moscovium have been produced.

Moscovium was called ununpentium (IUPAC system) or eka-bismuth (Mendeleev's naming system) before its official discovery. Most people simply referred to it as "element 115". When the IUPAC requested the discoverers propose a new name, they suggested langevinium, after Paul Langevin. However, the Dubna team brought up the name moscovium, after the Moscow Oblast where Dubna is located. This is the name the IUPAC endorsed and approved.

All isotopes of moscovium are expected to be extremely radioactive. The most stable isotope to date is moscovium-290, which has a half-life of 0.8 seconds. Isotopes with masses ranging from 287 to 290 have been produced. Moscovium is at the edge of the island of stability. It is predicted Moscovium-291 might have a long half-life of several seconds.

Until experimental data exists, moscovium is predicted to behave much like a heavy homolog of other pnictogens. It should be most like bismuth. It is expected to be a dense solid metal that forms ions with 1+ or 3+ charges.

At present, the only use for moscovium is for scientific research. Possibly one of its most important roles will be for the production of other isotopes. One decay scheme of element 115 leads to the production of copernicium-291. Cn-291 is in the middle of the island of stability and may have a half-life of 1200 years.

The only known source of moscovium is nuclear bombardment. Element 115 has not been observed in nature and serves no biological function. It's expected to be toxic, certainly because it is radioactive, and possibly because it could displace other metals in biochemical reactions.

Moscovium Atomic Data

Since so little moscovium has been produced to date, there is not a lot of experimental data on its properties. However, some facts are known and other may be predicted, mainly based on the electron configuration of the atom and the behavior of elements located directly above moscovium on the periodic table.

Element Name: Moscovium (formerly ununpentium, which means 115)

Atomic Weight: [290]

Element Group: p-block element, group 15, pnictogens

Element Period: Period 7

Element Category: probably behaves as a post-transition metal

State of Matter: predicted to be a solid at room temperature and pressure

Density: 13.5 g/cm³ (predicted)

Electron Configuration: [Rn] 5f¹⁴ 6d¹⁰ 7s² 7p³ (predicted)

Oxidation States: predicted to be 1 and 3

Melting Point: 670 K  (400 °C, 750 °F) (predicted)

Boiling Point: ~1400 K (1100 °C, 2000 °F) (predicted)

Heat of Fusion: 5.90–5.98 kJ/mol (predicted)

Heat of Vaporization: 138 kJ/mol (predicted)

Ionization Energies:

• 1st: 538.4 kJ/mol (predicted)
• 2nd: 1756.0 kJ/mol (predicted)
• 3rd: 2653.3 kJ/mol (predicted)

Atomic Radius: 187 pm (predicted)

Covalent Radius: 156-158 pm (predicted)