Flerovium (Fl)
Element 114 · Post-transition metal · atomic mass [289] u · group 14, period 7
Electron shells: 2, 8, 18, 32, 32, 18, 4
Flerovium sits near the predicted "island of stability", where superheavy nuclei should last much longer than their neighbours. Its isotopes do survive noticeably longer than expected.
Flerovium is the best current evidence that the theorised "island of stability" is real.
- Atomic number
- 114
- Atomic mass
- [289] u
- Electron configuration
- [Rn] 7s² 7p² 5f¹⁴ 6d¹⁰
- Group · period · block
- 14 · 7 · p
- Oxidation states
- 0, +1, +2, +4, +6
- Electronegativity
- Not measured
- Melting point
- —
- Boiling point
- —
- Density
- Not measured
- State at 20 °C
- Unknown
- Appearance
- Unknown; presumed metallic
- Discovered
- Joint Institute for Nuclear Research, Dubna, 1998
114 protons, and 114 electrons when neutral
Mass number of the longest-lived isotope — no standard atomic weight exists
Predicted, not measured
Carbon group
What Flerovium is used for
- Scientific research only
Atomic structure of Flerovium
A neutral flerovium atom has 114 protons and 114 electrons. Its most common isotope carries about 175 neutrons, which is where the mass number 289 comes from. Change the neutron count and you have a different isotope of flerovium; change the proton count and you have a different element entirely.
Those electrons fill shells from the inside out: 2, 8, 18, 32, 32, 18, 4. In orbital notation that is [Rn] 7s² 7p² 5f¹⁴ 6d¹⁰, leaving 4 valence electrons in the outer shell — the ones that do the chemistry.
3D electron orbitals
See where Flerovium's electrons actually are — a cloud of 26,000 points sampled from the probability density |ψ|², not a cartoon of a lobe.
Where Flerovium sits in the periodic table
Discovery and naming
Flerovium was discovered by Joint Institute for Nuclear Research, Dubna in 1998. Its name comes from The Flerov Laboratory, named for Georgy Flerov.
Every isotope of flerovium is radioactive, so it has no standard atomic weight. Periodic tables show the mass number of its longest-lived isotope in square brackets instead.
Keep exploring
Atomic weight from IUPAC/CIAAW; physical properties from PubChem (US National Library of Medicine). Values that have never been measured are shown as “not measured” rather than estimated.
Related Calculators
Frequently Asked Questions
What is the atomic mass of Flerovium?
Flerovium has no stable isotope, so it has no standard atomic weight. Periodic tables instead show 289 in square brackets — the mass number of its longest-lived isotope.
How many protons, neutrons and electrons does Flerovium have?
Flerovium has 114 protons, because the atomic number is the proton count and that is what makes an atom Flerovium at all. A neutral Flerovium atom has the same number of electrons, 114. The neutron count varies by isotope; the most common one has about 175, since 289 − 114 = 175.
What is the electron configuration of Flerovium?
The electron configuration of Flerovium is [Rn] 7s² 7p² 5f¹⁴ 6d¹⁰, though for an element this heavy the configuration is predicted from theory rather than measured. Its electrons are arranged 2, 8, 18, 32, 32, 18, 4 across 7 shells.
Is Flerovium a metal?
Yes. Flerovium is classified as a post-transition metal, on the metallic side of the table.
What group and period is Flerovium in?
Flerovium is in group 14 (the carbon group), period 7, in the p-block. The group is its column and the period is its row.
What is Flerovium used for?
Scientific research only. Flerovium sits near the predicted "island of stability", where superheavy nuclei should last much longer than their neighbours.
Who discovered Flerovium, and where does its name come from?
Flerovium (Fl) was discovered by Joint Institute for Nuclear Research, Dubna in 1998. The name comes from The Flerov Laboratory, named for Georgy Flerov.
Is Flerovium radioactive?
Yes. Every isotope of Flerovium is radioactive — it has no stable form at all, which is why the periodic table shows its mass in square brackets rather than as a standard atomic weight.