Oganesson, designated by the symbol Og and atomic number 118, stands as a synthetic, superheavy, and highly radioactive element. It holds the distinction of being the heaviest element currently recognized on the periodic table. The first successful synthesis of Oganesson occurred in 2002 at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia. This achievement was the result of a collaborative effort between Russian and American scientists, with its official announcement following in 2006.
The Unobservable Reality
Oganesson has never been directly observed in a quantity large enough to be seen with the naked eye. This is because it is purely synthetic and does not exist naturally on Earth.
Scientists have produced only a minuscule number of Oganesson atoms; merely five atoms of its only confirmed isotope, Oganesson-294, have been created. This isotope is extremely radioactive, possessing an exceptionally short half-life of approximately 0.7 milliseconds. Any atoms generated decay almost instantly, making it impossible to accumulate enough material for a visible sample or to study its bulk physical properties.
Scientific Predictions of Its Nature
Despite the inability to observe Oganesson directly, scientists predict its characteristics based on its position in Group 18 of the periodic table, alongside the noble gases. Theoretical calculations indicate that Oganesson’s immense atomic number leads to significant relativistic effects on its electrons. These effects cause its electron structure to behave differently from lighter noble gases, influencing its expected properties.
Due to these relativistic influences and stronger van der Waals forces, Oganesson is predicted to be a solid at room temperature, a stark contrast to other noble gases which are typically gaseous. Its predicted melting point is around 325 Kelvin (approximately 52 degrees Celsius), with a boiling point estimated at 450 Kelvin (around 177 degrees Celsius). These relativistic effects are also expected to make Oganesson more chemically reactive than its lighter Group 18 counterparts, potentially allowing it to form compounds, which is unusual for a noble gas. Calculations suggest it might exhibit semiconducting properties.
How Oganesson is Known to Exist
The existence of Oganesson is confirmed through nuclear synthesis and the detection of its decay products. It is produced by bombarding a target of Californium-249 (249Cf) with Calcium-48 (48Ca) ions in a particle accelerator, such as a cyclotron. This highly energetic collision results in the fusion of atomic nuclei, briefly forming an Oganesson atom.
Scientists infer Oganesson’s creation by detecting the characteristic “fingerprint” of its decay chain. The Oganesson-294 isotope primarily undergoes alpha decay, emitting an alpha particle and transforming into Livermorium-290 (290Lv). Scientists meticulously track these subsequent decay products, confirming Oganesson’s fleeting existence.