Flerovium (Fl)

Flerovium is the closest thing yet reached to the predicted island of stability: 114 protons is thought to be a magic number, and flerovium isotopes last seconds where their neighbours last milliseconds. Whether it is a metal or a volatile gas is genuinely open — some experiments have it sticking to gold like a metal, others have it behaving more like a noble gas, and the disagreement comes down to a handful of atoms in each case. It is named for Georgy Flerov, who founded the Dubna laboratory and who in 1942 wrote to Stalin pointing out that Western journals had stopped publishing on fission, which meant they were building a bomb.

Properties

Atomic number

114

Symbol

Fl

Mass number of most stable isotope

[289]

Category

Post-transition metal

Group

14

Period

7

Block

p-block

Electron configuration

[Rn] 7s² 5f¹⁴ 6d¹⁰ 7p²

Electrons per shell

2, 8, 18, 32, 32, 18, 4

Oxidation states

+2, +4, 0

Discovered

1998 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 7p²

Noble gas shorthand

[Rn] 7s² 5f¹⁴ 6d¹⁰ 7p²

Shells

K: 2 · L: 8 · M: 18 · N: 32 · O: 32 · P: 18 · Q: 4

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 exists and even the physical state is disputed. The mass given is the mass number of flerovium-289, the longest-lived at roughly 2 seconds.

Several physical properties are not listed for flerovium 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 14

Elements in the same group share their outer electron count, which is why they behave similarly in reactions. Flerovium sits in group 14 with carbon, silicon, germanium, tin, lead.