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 oganesson 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.
Size, to scale
Radius 247 pm — that is 0.247 nm, so about 2024 million of them side by side would span a millimetre.
Thermal range
Oganesson is liquid over a 125 K window, from 325 K to 450 K.
The story
The heaviest element ever made, and the only one named after a living person at the time.
Ultimate Russian Achievement: Oganesson discovery represents the crowning achievement of Russian superheavy element research, accomplished by Yuri Oganessian's team at the Joint Institute for Nuclear Research in Dubna, establishing Russia as the world leader in pushing the periodic table to its absolute limits.
Four-Year Ultimate Challenge: The oganesson discovery required four years of the most challenging nuclear physics experimentation ever attempted from 2002 to 2006, involving technological innovations that pushed particle accelerator science to its absolute maximum capabilities.
Oganessian's Legacy: Led by Yuri Oganessian, the discovery team achieved what many considered impossible, creating the heaviest element ever synthesized and completing the seventh period of the periodic table through unprecedented scientific dedication and innovation.
Significant Technical Mastery: Creating oganesson required developing the advanced ion beam focusing systems, the most sensitive particle detection methods, and the most sophisticated data analysis techniques in the history of nuclear physics research.
IUPAC Ultimate Recognition: The International Union of Pure and Applied Chemistry officially recognized JINR's discovery in 2015, granting naming rights to honor Yuri Oganessian himself. "Oganesson" represents the first element named after a living scientist since seaborgium.
Historic Scientific Pinnacle: Oganesson's discovery represents humanity's greatest achievement in superheavy element synthesis, demonstrating that even the most seemingly impossible scientific goals can be accomplished through extraordinary dedication and technological innovation.
Global Scientific Impact: The achievement represents the ultimate validation of theoretical nuclear physics models and has inspired continued exploration toward discovering elements beyond the current periodic table limits.
Applications
Period 7 Completion Studies: Oganesson holds the distinction of completing the seventh period of the periodic table, making it crucial for understanding periodic trends and validating theoretical predictions about the heaviest possible elements that can be synthesized with current technology.
Noble Gas Chemistry Revolution: As the heaviest noble gas, oganesson offers unprecedented opportunities to study how relativistic effects completely transform chemical behavior. Theoretical predictions suggest oganesson might be a solid with metallic properties, revolutionizing noble gas chemistry understanding.
Island of Stability Exploration: Oganesson research provides crucial data about nuclear stability in the superheavy element region, offering insights into whether the theorized "island of stability" might be accessible with future technological advances in element synthesis.
Relativistic Quantum Mechanics Testing: Oganesson represents a leading testing ground for quantum mechanical models of atomic structure under extreme conditions, providing experimental data to validate or refute theoretical predictions about electron behavior in superheavy atoms.
Superheavy Element Synthesis Limits: Creating oganesson pushes particle accelerator technology to its absolute limits, providing insights into the maximum atomic number achievable with current nuclear physics techniques and guiding future technological development.
International Scientific Culmination: Oganesson research represents a high point of international cooperation in fundamental science, requiring the combined expertise and resources of multiple nations to achieve humanity's most challenging nuclear synthesis goals.
Future Technology Vision: While currently limited to individual atoms, understanding oganesson's properties contributes to the ultimate scientific goal of discovering stable superheavy elements that might revolutionize technology in ways that transcend current human imagination.
Maximum Particle Accelerator Challenge: Oganesson exists only within the world's most powerful nuclear physics facilities, requiring months of continuous operation at maximum energy to produce individual atoms in what represents humanity's most challenging scientific synthesis achievement.
Ultimate Nuclear Reaction Studies: Scientists use oganesson synthesis to understand the absolute limits of heavy-ion fusion processes and nuclear reaction dynamics, advancing fundamental knowledge of nuclear physics at the extremes of possibility.
Theoretical Chemistry Ultimate Test: Oganesson provides a leading experimental challenge for quantum mechanical predictions about superheavy element chemistry, particularly theories suggesting complete transformation of noble gas properties due to relativistic effects.
Supreme Instrumentation Innovation: Oganesson detection requires the most sophisticated particle identification systems ever developed, driving innovation in nuclear instrumentation that represents a high point of human technological achievement.
Elite Scientific Training: Oganesson experiments provide a leading training opportunity for nuclear physicists, representing the most challenging and prestigious research possible in superheavy element science and nuclear physics.
Ultimate International Cooperation: Oganesson studies require coordination between the world's premier nuclear physics laboratories, representing the highest level of international scientific collaboration and knowledge sharing.
Where it comes from
0 mg/kg of Earth's crust · more abundant than 0% of elements
Complete Natural Impossibility: Oganesson cannot form through any conceivable natural nuclear processes occurring anywhere in the universe. Its 118-proton nucleus represents the absolute limit of nuclear instability, making natural formation physically impossible under any known conditions.
Ultimate Laboratory Challenge: Every oganesson atom has been artificially created through the most challenging nuclear fusion reactions possible with current technology. The process requires bombarding californium-249 targets with calcium-48 ions, achieving success rates of individual atoms per month.
Cosmic Absolute Impossibility: Even the most extreme cosmic events imaginable, including neutron star collisions and the cores of the most massive stars, completely lack the conditions necessary to create and preserve oganesson nuclei.
Supreme Facility Requirement: Oganesson exists only in humanity's advanced nuclear physics installation, the Joint Institute for Nuclear Research in Russia, representing the absolute pinnacle of human nuclear research capabilities and technological achievement.
Ultimate Nuclear Instability: Oganesson's synthetic nature represents the extreme limit of nuclear physics principles. With 118 protons, electromagnetic repulsion completely overwhelms nuclear forces, creating the most unstable atomic nucleus ever created.
Future Impossibility: Even revolutionary future accelerator technologies cannot make oganesson naturally occurring due to its fundamental nuclear instability and tendency toward immediate radioactive decay upon formation.
Handling
Oganesson is radioactive. It has no stable isotope — every nucleus decays. Handling requires appropriate shielding and licensing.
Instantaneous High-Energy Decay: Oganesson undergoes alpha decay with an extremely short half-life measured in milliseconds, emitting the highest-energy alpha particles of any known element. Even single atoms represent extreme radiation hazards requiring high containment.
Ultimate Containment Requirements: All oganesson research occurs within the most heavily shielded nuclear facility on Earth, featuring multiple redundant containment systems, the most sophisticated remote handling equipment available, and continuous radiation monitoring at maximum sensitivity.
Maximum Radioactive Hazard: Oganesson decay produces a cascade of extremely radioactive daughter nuclei, each presenting severe radiation risks. The complete decay chain represents one of the most dangerous radioactive sequences known to science.
World's Most Qualified Personnel: Oganesson research requires the planet's most experienced nuclear physicists with decades of radiation safety training and exceptional expertise in handling the most dangerous radioactive materials ever created.
Absolute Remote Operation: Oganesson's extreme radioactivity makes any form of direct handling absolutely impossible. All synthesis, detection, and analysis occur through the advanced remote-controlled systems ever developed for scientific research.
Ultimate Environmental Protection: Despite producing only individual atoms, oganesson research facilities maintain the most stringent environmental monitoring and radioactive waste management protocols possible to ensure absolute containment of the most dangerous radioactive materials known to humanity.
Quick answers
Oganesson (symbol Og) is element 118 on the periodic table, a noble gas in period 7, group 18. The heaviest element ever made, and the only one named after a living person at the time. At room temperature it is a solid, and it is radioactive.
[Rn] 5f¹⁴ 6d¹⁰ 7s² 7p⁶, giving 7 occupied shells holding 2, 8, 18, 32, 32, 18, 8 electrons respectively. Its outer shell holds 8 electrons, which is what sets its bonding behaviour.Oganesson melts at 325 K (51.9 °C) and boils at 450 K (176.9 °C).
Oganesson has no stable isotope, so it has no standard atomic weight. The figure quoted, 294, is the mass number of its longest-lived known isotope.
Oganesson has a density of 5 g/cm³. Water is 1.0 g/cm³, so a block of oganesson is about 5× heavier.
Oganesson was discovered in 2002 by JINR Dubna & Livermore. It is named after yuri Oganessian, nuclear physicist.
Oganesson does not occur naturally on Earth in any meaningful quantity — it is made in a reactor or an accelerator.
Yes. Oganesson has no stable isotope — every one of its nuclei decays. It does not occur in usable quantities in nature and must be synthesised.