Moscovium (Mc)

Moscovium is named after Moscow Oblast, where Dubna sits. Its main scientific role has been as a stepping stone: tennessine was confirmed partly by matching its decay chain against moscovium's, since element 117 decays into element 115. It is also the subject of one of the odder pieces of fringe folklore — Bob Lazar's 1989 claim that "element 115" fuels alien spacecraft, made fourteen years before anyone synthesised it, and comprehensively at odds with an isotope that falls apart in under a second.

Properties

Atomic number

115

Symbol

Mc

Mass number of most stable isotope

[290]

Category

Post-transition metal

Group

15

Period

7

Block

p-block

Electron configuration

[Rn] 7s² 5f¹⁴ 6d¹⁰ 7p³

Electrons per shell

2, 8, 18, 32, 32, 18, 5

Oxidation states

+1, +3

Discovered

2003 by Yuri Oganessian and colleagues at Dubna, with Lawrence Livermore

Electron configuration

Full

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f¹⁴ 6d¹⁰ 7p³

Noble gas shorthand

[Rn] 7s² 5f¹⁴ 6d¹⁰ 7p³

Shells

K: 2 · L: 8 · M: 18 · N: 32 · O: 32 · P: 18 · Q: 5

What it is used for

• Research only; no application outside the laboratory

Hazards

• Intensely radioactive; exists only as individual atoms in an accelerator

Melting point, boiling point, density and electronegativity are omitted: no measurement is possible. The mass given is the mass number of moscovium-290, the longest-lived at roughly 0.65 seconds.

Several physical properties are not listed for moscovium because no bulk sample has ever existed. Only a handful of atoms have been produced, often with half-lives measured in seconds, so published melting points and densities for elements in this range are calculations rather than measurements. They are omitted rather than presented as observed values.

Neighbours in the table

Group 15

Elements in the same group share their outer electron count, which is why they behave similarly in reactions. Moscovium sits in group 15 with nitrogen, phosphorus, arsenic, antimony, bismuth.