Physicists are confident that elements heavier than oganesson (element 118, the current last entry on the periodic table) can exist, and several laboratories around the world are actively racing to create elements 119 and 120 right now. Whether the periodic table has a hard endpoint somewhere further out is a genuinely open question, one that sits at the intersection of nuclear physics, quantum chemistry, and even astrophysics. The answer depends on what you mean by “element” and how long it needs to survive before it counts.
Where the Periodic Table Stands Today
The periodic table currently holds 118 confirmed elements. The first 94 occur naturally (though some, like technetium and promethium, exist on Earth only in trace amounts). Everything from element 95 onward has been synthesized in laboratories, typically by smashing lighter nuclei together at enormous speeds and hoping a few of them fuse rather than shatter. The heaviest four elements, nihonium (113), moscovium (115), tennessine (117), and oganesson (118), were confirmed and named only in 2016, completing the table’s seventh row. The criteria for claiming discovery of a new element are maintained jointly by the International Union of Pure and Applied Chemistry (IUPAC) and the International Union of Pure and Applied Physics (IUPAP), which recently reviewed those criteria in anticipation of new claims beyond element 118.
The Race to Make Elements 119 and 120
Three major research groups are competing to synthesize element 119, which would open the eighth row of the periodic table. Japan’s RIKEN laboratory is bombarding curium-248 targets with a beam of vanadium-51 ions. Russia’s Joint Institute for Nuclear Research (JINR) and China’s Institute of Modern Physics are each planning to try multiple beam-target combinations, including americium-243 plus chromium-54 and berkelium-249 plus titanium-50.1ACS Central Science. How Japan Took the Lead in the Race to Discover Element 119 All of these are “hot fusion” reactions, meaning the collision releases several neutrons and produces a highly excited nucleus that may or may not survive long enough to be detected.
The technical challenge is staggering. Cross-sections for these reactions (a measure of how likely the fusion event is to succeed) are incredibly small. Researchers may need to run experiments for months or years, firing trillions of projectile ions per second, to produce even a single atom of element 119. Element 120 presents an even steeper challenge because the heavier combined nucleus is harder to hold together. Theoretical calculations suggest that element 119 nuclei could undergo alpha decay (shedding pairs of protons and neutrons) up to a mass number of about 318, beyond which they would instead break apart through spontaneous fission. Element 120 nuclei are predicted to reach their fission threshold even sooner, around mass number 309.2Modern Physics Letters A. Half-lives and fragments of spontaneous fission of superheavy elements
The Island of Stability
One of the most tantalizing ideas in nuclear physics is that beyond the short-lived superheavy elements we have made so far, there may be a region where certain combinations of protons and neutrons form especially stable configurations. This concept is often called the “island of stability.” Just as certain numbers of electrons create chemically stable noble gases, certain “magic numbers” of protons and neutrons create nuclei that resist decay far longer than their neighbors would suggest.
The predicted center of this island lies near 114 protons and 184 neutrons. Experimental work has already shown hints of enhanced stability near different nuclear shell closures at 108 protons and 162 neutrons.3Radiation Physics and Chemistry. Towards the “islands of stability” of superheavy elements – Section: Abstract The elements we have synthesized so far in this region, like flerovium (114) and livermorium (116), do live a bit longer than some of their lighter superheavy neighbors, lasting fractions of a second rather than thousandths of a second. But we have not yet been able to produce isotopes with enough neutrons to reach the predicted sweet spot at neutron number 184. Getting there would require either new reaction methods or target materials that are themselves extraordinarily rare and radioactive.
If the island of stability is real and accessible, some superheavy isotopes might last minutes, hours, or conceivably even longer. That would be transformative for the field, because it would mean scientists could actually study the chemistry of these elements rather than just confirming they existed for a fleeting instant.
Is There a Hard Limit to the Periodic Table?
This is where things get genuinely uncertain. There are at least two different ways the periodic table could end, and they involve different physics.
The first is a nuclear limit. At some point, no combination of protons and neutrons can form a nucleus that holds together even briefly. Theoretical models that calculate fission barriers (the energy hump a nucleus must overcome to split apart) have mapped out predictions for thousands of possible nuclei between the lightest superheavy elements and the heaviest conceivable ones. One large-scale study calculated fission barriers for over 5,200 nuclides with mass numbers between 171 and 330, using more than five million different nuclear shapes to find each barrier height.4DOE PAGES / Physical Review C. Fission barriers at the end of the chart of the nuclides The general trend is that barriers shrink as you add more protons, meaning nuclei become progressively easier to split. Somewhere around element 120 to 130, depending on the model, fission barriers may essentially vanish, and any nucleus that forms would fly apart almost instantly.
The second limit is electronic. Each element is defined by its number of protons, and each proton attracts electrons to fill orbitals. But as the nuclear charge grows, the innermost electrons are pulled so close to the nucleus that they approach the speed of light. This makes the periodic table’s familiar pattern of chemical families start to break down. At extremely high atomic numbers (some estimates put this around element 170 or so), quantum electrodynamics models suggest that the electric field near the nucleus could become strong enough to spontaneously create electron-positron pairs from the vacuum, a phenomenon that would make the very concept of a neutral atom with a well-defined electron cloud meaningless. The practical limit almost certainly arrives well before this exotic threshold, but the nuclear limit around element 120 to 130 is the more immediate barrier researchers are focused on.
Relativistic Effects Already Reshape Superheavy Chemistry
You do not need to reach element 170 for relativity to matter. It is already dramatically reshaping the chemistry of elements we have made. When electrons move at a substantial fraction of the speed of light, their orbitals contract and shift in energy, changing how the atom bonds with other atoms. This is well established across the heavier parts of the periodic table, affecting everything from gold’s color to mercury being a liquid at room temperature.5Coordination Chemistry Reviews. Relativistic effects on the chemical bonding properties of the heavier elements and their compounds – Section: Abstract
For superheavy elements, relativistic effects are so strong that the elements no longer behave like lighter members of the same column in the periodic table. Gas chromatography experiments on nihonium (element 113) and moscovium (element 115) showed that both interact more weakly with silicon oxide surfaces than their lighter counterparts thallium and bismuth. At the same time, they turned out to be more reactive than their immediate neighbors copernicium (112) and flerovium (114), which have closed or nearly closed electron shells.6PubMed Central. Manifestation of relativistic effects in the chemical properties of nihonium and moscovium revealed by gas chromatography studies This means the periodic table’s predictive power, its ability to tell you how an element will behave based on its position, weakens significantly in the superheavy region. If elements 119 and beyond are ever produced in quantities large enough for chemistry, they may defy expectations in ways that are difficult to anticipate even with sophisticated calculations.
Doing Chemistry One Atom at a Time
A practical reality that shapes every aspect of superheavy element research is that these atoms are produced individually. You do not get a test tube of element 115. You get one atom, it exists for less than a second, and you have to learn everything you can from that single atom before it decays. Researchers have developed remarkable techniques to study chemistry under these constraints, essentially performing gas-phase chromatography on individual atoms as they travel through a detector array.
To prepare for future experiments with moscovium, for instance, one group recently studied the behavior of a short-lived bismuth isotope (bismuth-211, which sits just above moscovium in the periodic table) under controlled gas-phase conditions, using different carrier gases and a specialized chromatography and detection setup.7Radiochimica Acta. Single-atom-at-a-time adsorption studies of 211Bi and its precursor 211Pb on SiO2 surfaces By understanding how the lighter analog behaves, researchers can design experiments that will catch the heavier element’s brief appearance and extract meaningful chemical data from it. This kind of methodical groundwork is happening at several facilities worldwide, each building the experimental infrastructure needed before the superheavy atoms even arrive.
Could Superheavy Elements Exist in Nature?
Every superheavy element discovered so far was made in a laboratory, but that does not mean nature has never produced them. The universe has at least one mechanism that could, in principle, forge elements well beyond uranium: the rapid neutron capture process, or r-process, which occurs when atomic nuclei are flooded with neutrons so quickly that they capture many before they have a chance to decay. The first direct observational evidence that neutron star mergers drive this process came in 2017, when the kilonova AT2017gfo was detected alongside gravitational waves from merging neutron stars.8Monthly Notices of the Royal Astronomical Society. Neutron star mergers as the dominant contributor to the production of heavy r-process elements – Section: ABSTRACT
Whether the r-process can reach all the way to the island of stability is debated. In principle, the neutron flux in a neutron star merger is intense enough to push nuclei to very high mass numbers. If long-lived superheavy isotopes were produced, they might survive long enough to be incorporated into interstellar dust, planetesimals, and eventually planets or meteorites. Researchers have looked for evidence of this. The Long Duration Exposure Facility (LDEF) experiment collected cosmic ray tracks in space, obtaining the first statistically meaningful set of data on actinide-range nuclei in galactic cosmic rays, with 35 recorded tracks. Olivine crystals in meteorites have also attracted interest as potential archives of ancient superheavy nuclei because of their extremely long exposure to cosmic rays.9Nuclear Physics A. Searches for superheavy elements in nature: Cosmic-ray nuclei; spontaneous fission So far, no confirmed natural superheavy element has been found, but the search continues in cosmic rays, meteorites, and lunar samples.
What About Truly Exotic Matter?
When people ask about undiscovered elements “beyond the periodic table,” they sometimes mean something even more radical: forms of matter that do not fit the proton-neutron-electron framework at all. The most discussed candidate is strange quark matter, hypothetical chunks of matter containing roughly equal numbers of up, down, and strange quarks. If stable, small pieces of strange quark matter, called strangelets, would look like atoms with an absurdly high mass relative to their charge, nothing like any known element.
Searches for strangelets have been conducted in multiple settings. One team used the Yale accelerator as a mass spectrometer to look for strangelets in lunar soil, reasoning that the Moon’s surface, unshielded by an atmosphere, would have accumulated any stable exotic particles raining down from space.10PubMed. Search for stable strange quark matter in lunar soil The PAMELA space experiment also searched for strangelets in cosmic rays by looking for particles with anomalously high mass-to-charge ratios.11PubMed. New upper limit on strange quark matter abundance in cosmic rays with the PAMELA space experiment Neither search found evidence for strange quark matter, but the null results are still useful because they set upper limits on how common such matter could be. If strangelets exist, they are extremely rare in our cosmic neighborhood.
Strange quark matter would not really be an “element” in the chemical sense. It would not have electron orbitals, it would not form bonds, and it would not fit into any column of the periodic table. But it represents a genuinely different stable form of matter that, if discovered, would expand our understanding of what atomic-scale stuff the universe can produce.
Machine Learning and the Prediction Problem
One of the biggest obstacles in superheavy element research is that the theoretical models used to predict nuclear properties disagree with each other, sometimes substantially. Different models for calculating fission barriers, decay half-lives, and nuclear shell structure can give predictions that vary by orders of magnitude. This matters because experiments are so expensive and time-consuming that researchers need reliable predictions to choose which reactions to attempt and which isotopes to aim for.
Machine learning has recently entered this space as a way to improve predictions. Several groups have trained algorithms on known nuclear data and then used those models to predict properties of nuclei that have not been measured yet. One study used five different machine learning techniques to predict fission barriers for 330 even-even superheavy nuclei with proton numbers between 92 and 120.12Journal of Physics G: Nuclear and Particle Physics. Estimation of fission barrier heights for even–even superheavy nuclei using machine learning approaches Another applied gradient-boosting and neural network models to alpha decay and spontaneous fission half-lives, finding excellent agreement with known experimental values and generating predictions for unmeasured nuclei.13Journal of Physics G: Nuclear and Particle Physics. Modified empirical formulas and machine learning for α-decay systematics These tools will not replace physics-based models, but they are helping narrow down the vast landscape of possible superheavy nuclei and focus experimental effort where it is most likely to succeed.
Why New Elements Will Not Show Up in Your Medicine Cabinet
A natural follow-up question is whether any of these undiscovered elements would be useful for anything. The honest answer, at least for the foreseeable future, is almost certainly no. Every superheavy element produced so far has been created a few atoms at a time and has decayed in seconds or less. Even if island-of-stability isotopes turn out to last hours or days, the production rates are so low that accumulating a visible quantity of any element beyond oganesson is not a realistic prospect with current or near-future technology.
The value of discovering new elements is scientific rather than commercial. Each new element tests our understanding of how atomic nuclei hold together, how electron orbitals behave under extreme conditions, and where the laws of physics place boundaries on the kinds of matter that can exist. Flerovium and oganesson, for example, have already surprised researchers: oganesson’s electron cloud is predicted to be so smeared out by relativistic effects that it barely resembles a traditional noble gas. Every new element in this region is a stress test for quantum mechanics and nuclear theory in a regime that cannot be reached any other way.
There is also a deeper philosophical dimension. The periodic table is one of science’s most iconic organizational achievements. Finding out where it ends, whether row eight fizzles out after a few entries or stretches further than expected, tells us something fundamental about the universe’s toolkit for building matter. The fact that three countries are independently spending years of beam time and billions of yen, rubles, and yuan to produce a handful of atoms reflects how much that question matters to the physics community.
How Long Until Element 119 Is Confirmed?
Predictions are risky, but the experimental campaigns at RIKEN, JINR, and the Institute of Modern Physics have been running for several years, and optimism is cautious but real. RIKEN’s approach of using curium-248 plus vanadium-51 was chosen after careful theoretical screening of the most promising reactions.14ACS Central Science. How Japan Took the Lead in the Race to Discover Element 119 – Section: Picking a winner Even so, the expected production rate is so low that discovery could come tomorrow or could take another decade. The confirmation process itself adds time: IUPAC and IUPAP require independent replication or overwhelming statistical evidence before they will recognize a new element.15Pure and Applied Chemistry. On the discovery of new elements (IUPAC/IUPAP Report)
If and when element 119 is confirmed, it will be placed in group 1 of the periodic table, directly below francium, at least on paper. Whether it actually behaves like an alkali metal is a separate and fascinating question that relativistic effects may answer in surprising ways. Element 120, if it follows, would sit below radium in group 2. Beyond that, the map gets genuinely speculative, with theorists debating whether elements in the 120s and 130s would populate a new “g-block” of the periodic table or whether the orbital structure breaks down so thoroughly that assigning them to groups becomes meaningless. The periodic table has always been a living document, revised as understanding deepens. Its next chapter, whenever it arrives, will be written one atom at a time.