Fl · Element 114 · Post-transition metal
Predicted to sit in an "island of stability" where superheavy nuclei live far longer.
Structure
Not a diagram of dots on rings — a Monte-Carlo sample of the actual probability density |ψ|² for each occupied subshell. Drag to rotate. Blue and violet mark opposite signs of the wavefunction, which is what makes bonding possible.
Measured values
Every bar shows where flerovium sits among all 118 elements for that property.
Sources: IUPAC 2021 standard atomic weights · CRC Handbook of Chemistry and Physics · NIST. Values marked ~ are predicted rather than measured.
Same element, different neutrons
All flerovium atoms have the same number of protons, 114, and differ only in their number of neutrons: those variants are its isotopes. None of them is stable. The longest-lived known isotope, Fl-290, has 176 neutrons and a half-life of ~19 sec.
| ISOTOPE | Neutrons | Natural Abundance | Half-life | Decay Mode |
|---|---|---|---|---|
| Fl-286 | 172 | — | 166 ms | α (60%), SF (40%) |
| Fl-287 | 173 | — | 0.40 sec | α, SF |
| Fl-288 | 174 | — | 0.64 sec | α, SF |
| Fl-289 | 175 | — | 2.4 sec | α, SF |
| Fl-290 longest-lived | 176 | — | ~19 sec | ε/β⁺, SF, α |
Periodic tables list 289 for flerovium: the mass number of one long-lived isotope, not an average, so mass minus atomic number gives 175, the neutron count of Fl-289.
Decay modes
~ marks a half-life whose published uncertainty is larger than the value itself.
Data: IAEA Nuclear Data Section, LiveChart of Nuclides, ground-state evaluations, retrieved October 10, 2026. Abundance is the share of atoms in the natural element; a dash means the isotope has no standard natural abundance.
Size, to scale
Radius 247 pm — that is 0.247 nm, so about 2.02 million of them side by side would span a millimetre.
Thermal range
Flerovium is liquid over a 220 K window, from 200 K to 420 K.
The story
Predicted to sit in an "island of stability" where superheavy nuclei live far longer.
Russian Scientific Leadership: Flerovium discovery represents a triumph of Russian nuclear physics, achieved by an international team led by Yuri Oganessian at the Joint Institute for Nuclear Research in Dubna. This accomplishment continued Russia's proud tradition of superheavy element discoveries.
Decade-Long Research Program: The flerovium discovery spanned a decade of systematic experiments from 1999 to 2009, requiring persistent refinement of synthesis techniques and detection methods. The team's dedication through numerous failed attempts exemplifies scientific perseverance.
International Collaboration: While led by JINR, the discovery was made with Lawrence Livermore National Laboratory in the United States (GSI in Germany later confirmed the result in 2009). This collaboration demonstrated how fundamental science transcends national boundaries in pursuit of human knowledge.
Technical Breakthroughs: Creating flerovium required developing new target preparation techniques, ion beam optimization, and sophisticated particle detection systems. These innovations advanced the entire field of superheavy element research.
IUPAC Recognition: The International Union of Pure and Applied Chemistry officially recognized JINR's discovery in 2011, granting the team naming rights. "Flerovium" honors Georgy Flerov, founder of superheavy element research at JINR.
Scientific Legacy: Flerovium's discovery validated theoretical predictions about superheavy element synthesis pathways and opened new research directions toward the island of stability. The achievement inspired continued exploration of the periodic table's limits.
Global Impact: The discovery strengthened international cooperation in nuclear physics and demonstrated how advanced scientific facilities can achieve seemingly impossible goals through sustained effort and technological innovation.
Applications
Island of Stability Exploration: Flerovium represents a critical milestone in superheavy element research, positioned near the predicted "island of stability" where elements might exist for significantly longer periods. Its study provides crucial data about nuclear shell effects and the limits of atomic nuclei stability.
Relativistic Chemistry Studies: As element 114, flerovium offers unique opportunities to study how relativistic effects influence chemical bonding in superheavy elements. Early predictions suggested flerovium might behave like a noble gas, but 2022 experiments showed it to be a highly volatile metal, the least reactive member of group 14, making it a fascinating subject for computational chemistry validation.
Advanced Nuclear Physics: Flerovium synthesis requires fusion of calcium-48 with plutonium-244, pushing the boundaries of nuclear reaction understanding. These experiments advance knowledge of heavy-ion collision dynamics and nuclear fusion mechanisms at very high energies.
Detection Technology Development: Creating flerovium drives innovation in particle detection systems, timing electronics, and data acquisition methods. These technological advances benefit broader scientific fields including medical physics, materials science, and space exploration.
International Collaboration Framework: Flerovium research exemplifies global scientific cooperation, with teams from Russia, Germany, and the United States sharing resources and expertise to achieve common goals in fundamental science.
Theoretical Model Testing: Flerovium provides experimental data to test quantum mechanical models of atomic structure, particularly theories about electron orbital behavior under very high nuclear charges and relativistic conditions.
Future Technology Foundation: Understanding flerovium's properties contributes to the long-term scientific goal of discovering stable superheavy elements that might transform technology in ways currently unimaginable.
Particle Accelerator Experiments: Flerovium exists only within specialized research facilities equipped with powerful cyclotrons and linear accelerators. Creating flerovium requires weeks of continuous bombardment to produce individual atoms, making each synthesis a remarkable scientific achievement.
Nuclear Decay Analysis: Scientists use flerovium to study alpha decay patterns and spontaneous fission processes, providing insights into nuclear stability mechanisms and the fundamental forces governing atomic nuclei behavior.
Computational Chemistry Validation: Flerovium serves as a testing ground for theoretical predictions about superheavy element chemistry, particularly models of its volatility, which 2022 experiments found to be that of a highly volatile metal, the least reactive in group 14.
Advanced Instrumentation Testing: Flerovium detection requires the most sophisticated particle identification systems available, driving development of new technologies that benefit multiple scientific disciplines.
Educational Research Value: Flerovium experiments provide training opportunities for nuclear physicists and graduate students, advancing human expertise in superheavy element science and nuclear instrumentation.
International Scientific Exchange: Flerovium research facilitates collaboration between world-leading nuclear physics laboratories, fostering knowledge sharing and technological advancement across national boundaries.
Where it comes from
0 mg/kg of Earth's crust · more abundant than 0% of elements
No Natural Occurrence: Flerovium has never been found in nature. Its 114-proton nucleus is far too unstable to survive in nature, so all known flerovium is artificial.
Laboratory Creation Only: Every known flerovium atom has been created through artificial nuclear fusion in particle accelerators. The process involves bombarding plutonium-244 targets with calcium-48 ions, achieving fusion rates of only a few atoms per day under optimal conditions.
Cosmic Absence: It is an open question whether the r-process in neutron star mergers briefly makes flerovium nuclei; none could survive. The element's short half-life means any hypothetically formed flerovium would decay before astronomical detection.
Accelerator Dependency: Flerovium has been produced only in highly specialized facilities like the GSI Helmholtzzentrum in Germany and the Joint Institute for Nuclear Research in Russia. These installations represent humanity's advanced capabilities in nuclear physics research.
Nuclear Instability Origins: Flerovium's synthetic nature results from fundamental nuclear physics principles. As atomic number increases, electromagnetic repulsion between protons increasingly overwhelms the strong nuclear force, preventing natural stability.
Future Synthesis Prospects: While improved accelerator technologies might enhance flerovium production efficiency, the element will remain synthetic due to its inherent nuclear instability and rapid radioactive decay.
Handling
Flerovium is radioactive. It has no stable isotope — every nucleus decays. Handling requires appropriate shielding and licensing.
Atom-by-Atom Production: Flerovium is made a few atoms at a time in heavy-ion accelerators. Only single atoms have ever been made, and no weighable amount has ever existed.
Half-Lives: Its isotopes decay mainly by alpha emission and spontaneous fission, with half-lives ranging from milliseconds to seconds, depending on the isotope.
No Meaningful Dose: Alpha particles cannot penetrate the outer layer of skin and could damage tissue only from inside the body, and single atoms are far too few to deliver any meaningful dose.
Where the Hazards Are: The hazards in this research come from the experiment, not the element: the accelerator beam, radioactive targets and activated equipment, and the waste these produce, which is managed as radioactive waste under national radiation protection rules.
Worker Protection: Staff follow the standard occupational radiation rules: annual dose limits, personal dose monitoring and keeping doses as low as reasonably achievable. Workers under 18 face much lower dose limits than adults: one tenth of the adult limits under US Nuclear Regulatory Commission rules (10 CFR 20.1207), and 1 mSv a year at US Department of Energy laboratories (10 CFR 835.207). A worker who declares a pregnancy is limited to 5 mSv to the fetus over the whole pregnancy (10 CFR 20.1208 and 835.206).
Quick answers
Flerovium (symbol Fl) is element 114 on the periodic table, a post-transition metal in period 7, group 14. Predicted to sit in an "island of stability" where superheavy nuclei live far longer. At room temperature it is expected to be a liquid, and it is radioactive.
[Rn] 5f¹⁴ 6d¹⁰ 7s² 7p², giving 7 occupied shells with the distribution 2, 8, 18, 32, 32, 18, 4. Its outer shell holds 4 electrons, which is what sets its bonding behaviour.No sample of flerovium has ever been condensed, so both figures are calculated rather than measured: it is predicted to melt at 200 K (-73.1 °C) and boil at 420 K (146.9 °C).
Flerovium has no stable isotope, so it has no standard atomic weight. The figure quoted, 289, is the mass number of Fl-289, the isotope periodic tables usually list; the longest-lived one in the IAEA data is Fl-290.
Flerovium has no stable isotope. Its longest-lived known isotope, Fl-290, has 176 neutrons (mass number 290 minus atomic number 114) and a half-life of ~19 sec. Periodic tables list 289 for flerovium, the mass number of one long-lived isotope, so mass minus atomic number gives 175, the neutron count of Fl-289.
Flerovium is predicted to have a density of about 14 g/cm³, though no sample large enough to weigh has ever been made. Water is 1.0 g/cm³ for comparison.
Flerovium was discovered in 1999 by JINR Dubna & Livermore. Origin of the name: the Flerov Laboratory.
Flerovium does not occur naturally on Earth in any meaningful quantity — it is made in a reactor or an accelerator.
Yes. Flerovium has no stable isotope — every one of its nuclei decays. It does not occur in usable quantities in nature and must be synthesised.