Flerovium · element 114
Sits under lead but might act like a noble gas, and it is the first landfall on the predicted island of stability
Key facts
For decades nuclear physicists pointed at element 114 as the place where superheavy atoms might suddenly become long-lived. Calculations showed that 114 protons could form a closed shell, a nuclear magic number, and that with 184 neutrons it might give nuclei surviving for years rather than milliseconds. When flerovium was made at Dubna in 1998 and 1999, the half-lives did climb, though not as far as hoped.
The element is named after Georgy Flyorov, the Soviet physicist who founded the Dubna laboratory that now carries his name. In 1942 he noticed that fission papers had vanished from Western journals, guessed that meant a secret bomb project, and wrote to Stalin urging the Soviet Union to start its own. Flerovium sits under lead in group 14, but whether it behaves like lead is a live debate.
Where it is found
Flerovium does not exist in nature. Its longest-lived known isotope survives for about two seconds. Every atom has been made artificially, and the total is around a hundred or so, more than for most superheavy elements because the reaction that produces it is comparatively generous.
That reaction is hot fusion using calcium-48. This rare isotope has eight more neutrons than ordinary calcium and makes up under 0.2 per cent of the natural element, so it is expensive to enrich. Beams of it strike plutonium-244 or 242 targets, giving flerovium-289, 288 or 287 after the hot compound nucleus sheds three or four neutrons. Flerovium also appears when livermorium emits an alpha particle.
How it was discovered
Yuri Oganessian's team at Dubna, working with Lawrence Livermore National Laboratory, reported a first candidate atom in December 1998. That event had an unusually long decay chain and has never been reproduced, so it is now thought to have been misassigned. Clearer results came in 1999 with flerovium-288 and 287, and over the following decade Dubna accumulated dozens of decay chains. GSI and Berkeley both confirmed the element in 2009.
IUPAC recognised the discovery in 2011 and approved the name flerovium in May 2012, with the symbol Fl. The Flerov Laboratory of Nuclear Reactions had by then made or co-made every element from 114 to 118, an achievement built on Oganessian's championing of calcium-48 beams when many considered the approach a long shot. Flyorov himself died in 1990.
What we use it for
Flerovium has no uses. Its importance is as a test of two big ideas at once: the island of stability in nuclear physics and the reach of relativity in chemistry.
On the first, flerovium partly delivered. Its isotopes live far longer than cold fusion products, and half-lives grow as neutrons are added, although the predicted centre at 184 neutrons remains out of reach. On the second, flerovium has been a puzzle. Relativity should stabilise the 7s and half of the 7p electrons so much that flerovium behaves almost like a noble gas. Dubna experiments around 2010 found it very volatile, but GSI work in 2014 showed it does bond to gold, weakly but like a metal. The consensus is that flerovium is the least reactive metal in group 14, but a metal nonetheless.
Reading the numbers
The atomic mass of 289 is the longest-lived isotope known. The rest are predictions. A melting point of about 340 kelvin, near 67 degrees Celsius, and a boiling point around 420 kelvin, about 147 degrees Celsius, would make flerovium a metal that melts in hot water, far below lead's 327 and 1749 degrees. The predicted density of about 14 grams per cubic centimetre is higher than lead's 11.3. None of this has been measured.
The configuration [Rn] 5f14 6d10 7s2 7p2 places flerovium in group 14. Relativistic splitting of the 7p shell puts its two 7p electrons in a stabilised sub-shell, so flerovium is expected to prefer +2 and to avoid +4 almost entirely, continuing the trend seen in lead. The low predicted melting and boiling points are themselves a sign of weak metallic bonding, and experiments confirm that flerovium is unusually volatile.
Safety and the environment
Flerovium is radioactive in every isotope, with half-lives up to about two seconds. It cannot accumulate, be stored or be released, and the hundred or so atoms ever made all decayed inside shielded accelerator halls. There is no flerovium in the environment and no route for public exposure.
Did you know?
- Calcium-48, the beam used to make flerovium, is less than 0.2 per cent of natural calcium and costs a great deal to enrich.
- Georgy Flyorov's 1942 letter to Stalin pointing out the sudden silence in Western fission research helped launch the Soviet atomic programme.
- The hypothetical isotope flerovium-298, with 184 neutrons, is the predicted heart of the island of stability, but no known reaction can reach it.
- If predictions hold, flerovium would melt at around 67 degrees Celsius, so a cup of hot tea could melt it.
- The very first flerovium event reported in 1998 was never seen again and is now thought to have been misidentified.
More in the superheavy elements
The nearest neighbours of flerovium in the family, by atomic number.
See all 15 superheavy elements on one page, or browse all 118 elements. Also listed under the post-transition metals.
Frequently asked questions
Who is flerovium named after?
Georgy Flyorov, the Soviet nuclear physicist who founded the laboratory at Dubna that now bears his name. The element was made at that laboratory, and the name was approved by IUPAC in 2012.
Is flerovium a noble gas?
No, but it is unusually unreactive for a metal. Relativistic effects make its outer electrons very stable, and early experiments suggested it might behave like a noble gas. Later work showed it does bond weakly to gold, so it is best described as a very volatile metal.
What is the island of stability?
It is a predicted region of superheavy nuclei with particular numbers of protons and neutrons that are unusually stable. Element 114 with 184 neutrons was long considered its centre. Known flerovium isotopes have fewer neutrons than that, but their half-lives do increase as neutrons are added, which supports the idea.
What is the half-life of flerovium?
The most stable known isotope, flerovium-289, has a half-life of about two seconds. Lighter isotopes decay in well under a second.
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Written by Anthony. Updated September 2026. Numerical data from Periodic-Table-JSON (CC BY-SA), cross-checked against the Flerovium reference article. Spotted an error? Tell us.