The seventh row of the periodic table is complete, ending at element 118, oganesson, but the table itself is far from finished. Scientists at multiple laboratories around the world are actively trying to create element 119 and beyond, pushing into an eighth row that no one has yet managed to open. Whether there is a hard ceiling on how many elements can exist remains an open question, with theoretical estimates placing the limit somewhere around element 120 to 170, depending on which physical constraint you consider the dealbreaker.
Where Row Seven Stands
The periodic table reached a tidy milestone in 2016 when four new elements received their official names and filled the last gaps in row seven: nihonium (113), moscovium (115), tennessine (117), and oganesson (118).1Polyhedron. Row 7 of the periodic table complete: Can we expect more new elements; and if so, when? That completed the row from francium at element 87 all the way across to oganesson, giving the table the rectangular shape most people recognize from a classroom wall. But “complete” here just means that every slot in the current layout is occupied. The layout itself was never supposed to stop at seven rows. There is no law of physics that says row seven is the last one; the question is whether human-made experiments or the structure of atomic nuclei impose a practical or absolute limit somewhere in the rows beyond.
The Race to Create Element 119
If element 119 is made, it would open period eight and sit directly below francium in the alkali metal column. Several teams are working toward that goal. Japan’s RIKEN laboratory has taken the lead in what amounts to an international race. In Germany, GSI ran a four-month experiment back in 2012 using a beam of titanium-50 fired at a berkelium-249 target but did not produce any atoms of element 119. More recently, Lawrence Berkeley National Laboratory made history by becoming the first team to create element 116 using a titanium-50 beam, an achievement described as an “essential precursor” to eventually making element 120 using the same kind of beam.2PubMed Central. How Japan took the lead in the race to discover element 119
The problem is not simply technical ambition. The heaviest elements can only be produced on an atom-at-a-time basis with extremely short half-lives, and their synthesis is among the most difficult experiments in modern science.3PubMed Central. Open questions on chemistry in the synthesis and characterization of superheavy elements To make one atom of element 119, researchers must smash two lighter nuclei together at precisely the right energy so that they fuse rather than simply shattering. The probability of fusion is astonishingly low. For the heaviest elements already confirmed, experiments have sometimes run for months before producing a single atom that survived long enough to be detected. Element 119 is expected to be even harder because the combined nuclear charge of the projectile and target pushes the electrostatic repulsion between protons higher, making fusion less likely.
Why the Elements Get Harder to Make
Every proton in a nucleus repels every other proton. The strong nuclear force holds them together, but its range is extremely short. As you pile more and more protons into a nucleus, you reach a point where the repulsive electromagnetic force starts winning. The nucleus becomes unstable and either splits apart through fission or sheds particles through radioactive decay almost instantly after forming.
Theoretical calculations suggest that certain superheavy nuclei up through element 120 could still be identified in the laboratory because their alpha-decay half-lives are shorter than their fission half-lives, meaning they would decay by emitting recognizable alpha particles rather than simply blowing apart.4Nuclear Physics A. Systematic study on the competition between α-decay and spontaneous fission of superheavy nuclei That distinction matters enormously for experimentalists. An alpha-decay chain produces a clear sequence of known daughter nuclei that scientists can trace backward to confirm what they created. If a nucleus just undergoes fission, the fragments look like a mess of lighter elements, and the evidence that you made something new is far weaker.
Beyond element 120, the picture gets murkier. The cross-sections for fusion reactions drop so sharply that even with the most intense particle beams and the most optimized targets, producing a single atom could take years of continuous bombardment. Some physicists suspect that elements 119 and 120 are reachable with current technology and enough patience, while anything beyond that may require entirely new experimental approaches or next-generation accelerators.
The Island of Stability
One of the most tantalizing ideas in nuclear physics is that somewhere in the superheavy region, there is an “island of stability” where certain combinations of protons and neutrons result in nuclei that are far more long-lived than their neighbors. The concept dates to the 1960s and 1970s, when Glenn Seaborg at Berkeley and Georgy Flerov at Dubna independently grew interested in predictions from the nuclear shell model. That model, originally developed by Maria Goeppert Mayer and Hans Jensen, suggested that nuclei with certain “magic numbers” of protons and neutrons would have unusually high binding energy, making them resist decay far longer than nearby nuclei.5PubMed. The transuranic elements and the island of stability
The commonly cited magic proton number for superheavy elements is 114 (flerovium), and early predictions placed a magic neutron number around 184. If a nucleus could be assembled with both of those magic numbers simultaneously, it might survive for minutes, hours, or even longer, which in the superheavy world would be extraordinary. In practice, though, no experiment has yet produced a nucleus with both magic numbers at once. The flerovium isotopes that have been made carry fewer neutrons than 184, and while they do show somewhat enhanced stability, they still decay within fractions of a second.
More recent calculations paint a richer and more complicated landscape. One large-scale study mapped shell-correction energies across thousands of even-even nuclei spanning proton numbers from 72 to 282 and identified 36 quasi-magic proton numbers and 53 quasi-magic neutron numbers, contributing to 133 deformed islands of stability scattered throughout the superheavy region.6Chinese Physics C. Islands of stability and quasi-magic numbers for super- and ultra-heavy nuclei The takeaway is that stability in the superheavy landscape is not one single island but more like an archipelago, with pockets of relative longevity appearing at various combinations of proton and neutron counts. Finding and reaching those pockets experimentally, however, remains a separate challenge from predicting them on paper.
Where the Table Might End
There is no single agreed-upon answer to the question “what is the last possible element?” because different physical effects set different limits, and which one bites first depends on the specific nuclear and electronic configuration.
One longstanding boundary comes from atomic physics rather than nuclear physics. As the number of protons increases, the innermost electrons must orbit faster to remain bound to such a powerful nucleus. At some point, the required speed approaches the speed of light, and relativistic effects become extreme. A recent analysis comparing the relativistic motion of the electron in a Bohr-like atom with the nuclear radius estimates that the heaviest element falls somewhere between element 122 and element 137.7Journal of Condensed Matter Nuclear Science. Relativistic Motion of the Electron and the Heaviest Element The upper bound of 137 has a long history in physics: it is the integer closest to the inverse of the fine-structure constant, and in a simplistic model, it is where the 1s electron would need to travel at light speed. More sophisticated quantum electrodynamic treatments push that number somewhat higher, into the 170s, but the exact boundary remains uncertain and depends on how you model the finite size and shape of the nucleus.
From the nuclear side, the limit may arrive even sooner. If no combination of protons and neutrons can hold together long enough to be detected, even in principle, then the table ends at the last nucleus that can exist for a measurable instant. Fission barriers drop and half-lives shorten drastically beyond element 120, and without hitting an island of stability, creation and detection become functionally impossible regardless of what the electron structure could support.
When Elements Stop Behaving as Expected
Even if new elements are created, they might not fit neatly into the columns of the periodic table. The periodic table is organized by recurring chemical properties: elements in the same column share similar behavior because they have similar outer electron configurations. But for the heaviest elements, relativistic effects scramble the electron orbitals in ways that can break those family resemblances.
Oganesson, element 118, is the most striking example so far. It sits in the noble gas column, below xenon and radon. Noble gases are famously unreactive and, well, gaseous. But state-of-the-art calculations show oganesson is neither. Two independent computational approaches found in excellent agreement that oganesson is a solid at room temperature, with a predicted melting point around 325 K (roughly 52 °C, or 125 °F). When the same calculations were run without including relativistic effects, the predicted melting point dropped to 220 K, which would make it a gas at room conditions, just as you would expect for a noble gas. Relativistic effects alone shift the melting point upward by about 100 K, turning what should be a gas into a solid.8PubMed Central. Oganesson: A Noble Gas Element That Is Neither Noble Nor a Gas
These are purely theoretical predictions, because oganesson’s half-life is so short (less than a millisecond for the known isotopes) that no one has ever collected enough atoms to measure its melting point or reactivity. But if the predictions hold, oganesson is a noble gas in name only. Its electron cloud is predicted to be so diffuse and uniformly distributed that it resembles a Fermi gas rather than the neatly layered shells of lighter noble gases. In plain terms, the electrons are smeared out into a nearly featureless cloud, which is profoundly weird for an element whose entire column identity is based on having a tightly closed electron shell.
This matters for the broader question of whether the periodic table can keep working as an organizing tool. If elements in the eighth row have properties that no longer match their column assignments, the table becomes less of a predictive map and more of a historical record. Some theorists have speculated that elements beyond 120 or so would need to be placed with footnotes or alternative layouts, because the relativistic mixing of orbitals makes traditional group assignments misleading.
What “Discovery” Actually Requires
Creating a new element is not enough to get it onto the periodic table. The International Union of Pure and Applied Chemistry (IUPAC) and the International Union of Pure and Applied Physics (IUPAP) jointly oversee a recognition process that demands rigorous evidence. A team must demonstrate that they produced a nucleus with a new number of protons and that it existed long enough to be detected. In practice, this means observing a characteristic decay chain: the new nucleus emits particles that produce known daughter nuclei, and the chain of decays matches theoretical predictions closely enough to rule out other explanations.
For the four most recently named elements, this process took years. The initial claims were published, then independently evaluated by a joint working group, and only after scrutiny were the discoveries officially recognized and the discoverers granted naming rights. Nihonium, for instance, was first reported in 2004 by RIKEN, but the element was not officially named until 2016. Element 119, whenever it is produced, will face the same gauntlet. A single event showing a plausible alpha-decay chain will likely not be enough; the experiment will need to be repeated, ideally by an independent laboratory, before the community accepts the result.
This is part of why the search is so slow. You are not just running an experiment until you see something; you are running it until you see something enough times, with enough statistical confidence, to survive a peer-review process that is appropriately skeptical of claims about once-in-history events.
Practical Implications of Superheavy Element Research
A reasonable question is why anyone would spend years and hundreds of millions of dollars trying to create atoms that vanish in milliseconds. The answer is partly about fundamental knowledge: the periodic table is one of the most powerful organizing frameworks in science, and learning where it breaks down tells us something deep about how matter works at extremes. The relativistic effects that turn oganesson into a solid, for instance, refine our understanding of quantum electrodynamics in strong fields, which has implications for everything from astrophysics to precision measurements of fundamental constants.
There are also practical spinoffs. The accelerator technology, detector systems, and target fabrication techniques developed for superheavy element research have found applications in nuclear medicine, materials science, and national security. The methods used to separate and identify single atoms amid a sea of background noise push the limits of analytical chemistry in ways that benefit other fields.
And if the island of stability turns out to be real in a robust sense, meaning that some superheavy isotopes survive for hours or days rather than milliseconds, the implications would be dramatic. Nuclei with half-lives long enough to accumulate in macroscopic quantities could have entirely new chemical and physical properties. Whether those properties would ever be useful is speculative, but the history of science is full of discoveries whose applications were unimaginable at the time of creation.
Could Nature Make Superheavy Elements Without Us?
One lingering question is whether superheavy elements exist anywhere in nature. The r-process, the rapid neutron-capture process that builds heavy elements during neutron star mergers and certain supernovae, can in principle push nuclei into the superheavy region. During an r-process event, a seed nucleus captures neutrons so fast that it does not have time to decay between captures, temporarily building up to very neutron-rich isotopes. As the neutron bombardment subsides, those nuclei undergo beta decay back toward stability, potentially passing through superheavy territory on the way.
Whether any superheavy nuclei produced in this way survive long enough to be detected in nature is another matter. If the island of stability exists and some of its isotopes have half-lives measured in millions or billions of years, then trace amounts of superheavy elements could in principle be present in certain ores or cosmic ray samples. Searches for naturally occurring superheavy elements have been conducted since the 1970s, examining everything from deep-sea sediments to meteorites. So far, none have been conclusively found. The searches continue, though, because the sensitivity of detection methods keeps improving, and a confirmed natural superheavy element would be a landmark finding in both nuclear physics and astrophysics.
Single-Atom Chemistry and the Limits of Characterization
Studying the chemistry of an element you can make only one atom at a time, and that atom lives for fractions of a second, requires ingenious workarounds. Researchers have developed gas-phase chromatography techniques that work on individual atoms, measuring how long a single atom sticks to a surface or how far it travels through a detector tube before decaying. These experiments provide information about volatility and chemical bonding, which can be compared to predictions and to the properties of lighter elements in the same column.
For elements through about 114, these single-atom experiments have been carried out with some success, and the results generally confirm that the periodic table’s group assignments hold up, with some deviations attributed to relativistic effects.3PubMed Central. Open questions on chemistry in the synthesis and characterization of superheavy elements Beyond 114, the half-lives are so short and the production rates so low that chemical characterization has not yet been possible. Oganesson’s predicted solid-state behavior, for example, remains purely computational. If element 119 is created, characterizing its chemistry would require producing it in quantities and with half-lives sufficient to at least perform gas-phase experiments, and that day may be far off even after the first atom is confirmed.
The gap between making an element and understanding it is growing wider with each step up the periodic table. For the lighter superheavy elements like rutherfordium and dubnium, enough atoms have been produced over the decades that some liquid-phase chemistry experiments have been attempted. For the newest elements, all we have are theoretical predictions checked, at best, by a single atom’s behavior in a chromatography tube. This growing reliance on theory rather than experiment is itself a challenge: if the theoretical models are wrong about the electron structure of these elements, we may not know until we can actually test them, which may not happen for years or decades.