oganesson294

Oganesson-294 (Og-294) is the isotope of the superheavy element oganesson (atomic number 118) with a mass number of 294. It is one of the heaviest and most short-lived nuclides produced in laboratories, existing only for fractions of a second before decaying.

Synthesis and discovery: Og-294 was first produced in 2006 by a collaboration between scientists at the Joint Institute for Nuclear Research in Dubna and Lawrence Livermore National Laboratory. The synthesis used a fusion reaction in which a californium-249 target was bombarded with a calcium-48 beam, yielding oganesson-294 through the evaporation of three neutrons (249Cf + 48Ca → 294Og + 3n). The isotope was identified by its characteristic alpha decays and the decay chains observed in detectors.

Properties and decay: Og-294 decays predominantly via alpha emission, with a half-life on the order of a fraction of a millisecond (roughly 0.7–0.9 ms in reported measurements). Its alpha decay leads to livermorium-290, followed by further decays of daughter nuclei. Because of its extremely short existence and the tiny production rates, Og-294 has no practical applications and is studied chiefly to advance understanding of nuclear structure at the extreme end of the periodic table.

Significance: The study of Og-294 helps test models of nuclear stability and shell structure in superheavy elements. While it lies outside the most neutron-rich predictions of the so-called island of stability, measurements of Og-294 and its decay properties inform theories about binding energies, decay modes, and the limits of chemical behavior for elements beyond oganesson.

Nomenclature: The element has the symbol Og and atomic number 118. Og-294 is named in honor of Yuri Oganessian for his contributions to superheavy-element research. The isotope designation is appended to the element name to indicate its mass number.