Oganesson and the Discovery of Element 118: The Heaviest Element and the Man Behind It

The podcast chronicles the journey to the heaviest element, oganesson, through the career of Yuri Oganessian and the collaborations that made its discovery possible. It also teases next week’s episode on melanin and its biological pigments.

• A look at cold fusion and hot fusion pathways used to synthesize superheavy elements, including the 1999 Berkeley claim and its retraction.
• The breakthrough in 2012 that provided the smoking gun for element 118, and the collaborative effort across major laboratories.
• The naming and public recognition of Yuri Oganessian, including Armenian stamps in 2017.
• A teaser for the next episode connecting biology and chemistry through eumelanin and related pigments.

Introduction

In the podcast, the Chemistry World team explores the chemistry of heavy elements and the remarkable career of Yuri Oganessian, a central figure in the discovery of the seventh row of the periodic table. The episode situates Oganessian in the context of the Joint Institute for Nuclear Research in Dubna and traces the long arc from early heavy element research to the modern synthesis of oganesson, element 118.

From Cold to Hot Fusion

The narrative describes two broad approaches to creating new elements through nuclear reactions. Cold fusion, which dominated attempts to extend the periodic table up to the late 1990s, aimed to yield Z values by slowing the fusion process. In the 1970s and 1980s Oganessian and his colleagues pursued cold fusion strategies that culminated in discoveries of elements 107 through 113. In contrast, hot fusion uses more energetic reactions to push the creation of heavier elements and relies on optimized target-projectile combinations to traverse higher atomic numbers. The episode emphasizes how these methods shaped the path to oganesson and the broader expansion of the periodic table’s seventh row.

The Berkeley Claim and Its Aftermath

A key moment discussed is the 1999 claim from a team at Lawrence Berkeley National Laboratory that an element with atomic number 118 had been produced by firing krypton into lead. The claim triggered intense scrutiny as other groups attempted to replicate the result. When replication failed, questions about data integrity and experimental reproducibility led to reexaminations and eventual retractions by all but one author, Viktor Nynow. This scandal, often referred to as a turning point in element discovery, underscored the importance of rigorous data handling in the frontier of synthetic chemistry and nuclear physics.

The Real Breakthrough

Despite the earlier controversy, the real creation of element 118 emerged from a collaboration between Oganessian’s team and Lawrence Livermore National Laboratory. By bombarding a californium target with calcium ions, researchers observed signals in 2002 that, after further verification, were eventually accepted in 2012 as definitive proof. A crucial detail was that berkelium, which powered part of the synthesis, decayed into californium during the experiment, enabling a chain of decays that traced the formation of oganesson. The element exhibited an extraordinarily short half life of less than 0.2 seconds, decaying through livermorium to flerovium and finally copernicium, providing the required experimental signature for confirmation of the element’s existence.

Name and Public Recognition

The naming of the element in honor of Oganessian elevated his profile on the world stage. Armenia honored him with stamps in 2017, a tribute connected to the discovery chain that confirmed the last element in the seventh row. The episode also highlights how large scientific collaborations and cross-institutional teamwork brought this achievement to fruition, with institutions including LLNL, Oak Ridge, Vanderbilt University, and Texas A&M University playing roles in the broader discovery program.

The Human Element and Future Prospects

The interview with Chemistry World reveals Oganessian’s humility about the meaning of the recognition and his insistence that much work remains. He emphasizes that collaboration was essential and that the story of heavy element discovery is ongoing, with future explorations of chemical space and new compounds to study as the periodic table continues to evolve. The podcast closes by noting that the series will return to the topic of exploring chemical space and hints at a future episode about more connections between chemistry and biology.

Next Week and Beyond

The discussion then shifts to a teaser for the next episode, where Kat Arney will discuss eumelanin, the pigment behind dark skin and hair, and its broader connections to biology and chemistry. The host invites listeners to share their ideas for compounds to cover in future episodes.

Conclusion

The podcast wraps with a sense of ongoing curiosity and collaboration, underscoring the idea that the chemistry world remains a dynamic field where discoveries build on a history of hard-won experiments and collective effort.