Oganesson

Description

The heaviest element yet made, and one of only two named after a person who was alive at the time (the other is seaborgium).

Physical Properties

Atomic Properties

Discovery & History

Synthesis at Dubna (2002 and 2005)

Oganesson was first made in 2002 at the Joint Institute for Nuclear Research in Dubna, Russia, by a Russian and American team led by Yuri Oganessian, with scientists from Lawrence Livermore National Laboratory in California. They bombarded californium-249 with calcium-48 ions and detected the decay of one atom of oganesson-294, possibly two, in 2002, and two more in 2005. The results were published in 2006.

An earlier, retracted claim

In 1999 a team at Lawrence Berkeley National Laboratory reported element 118 from a reaction of lead and krypton. Other laboratories could not repeat the result, and in 2001 the claim was withdrawn; in 2002 an investigation concluded that the data had been fabricated by one of the researchers.

Recognition and naming

In December 2015 the joint working party of IUPAC and IUPAP recognized the Dubna and Livermore team as the discoverers. The name oganesson, symbol Og, was approved in November 2016. It honors Yuri Oganessian, the nuclear physicist who led much of the work on the heaviest elements. He was alive when the name was approved, which had happened only once before, when seaborgium was named after Glenn Seaborg in 1997. The ending -on follows the pattern of the other noble gases, such as argon and xenon.

Isotopes

Data: IAEA Nuclear Data Section, LiveChart of Nuclides, ground-state evaluations, retrieved October 10, 2026. Abundance is the share of atoms in the natural element; a dash means the isotope has no standard natural abundance.

Applications & Uses

Research only

Oganesson has no practical uses. Only about five atoms have been detected, and each decayed within a few milliseconds of being made, so it cannot be collected, handled or put to work.

What scientists learn from it

Nuclear stability: how long oganesson-294 survives and how it decays test models of the heaviest nuclei, and of the predicted "island of stability", a region of longer-lived superheavy isotopes with more neutrons than can be made today.

Relativistic chemistry: oganesson is the main test case for calculations of how relativistic effects change chemical behavior at the bottom of the periodic table.

Making new elements: the actinide targets used to make oganesson are also used in attempts to make elements 119 and 120, combined with heavier beams such as titanium-50 and vanadium-51, because calcium-48 cannot reach beyond element 118.

Abundance