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What is Oganesson

Oganesson (pronunciation: oh-gan-ess-on) is a highly radioactive [2], artificially produced chemical element, classified as a non-metal, probably belonging to the group of noble gases [1, 3]. Represented by the symbol Og [3], Oganesson is a comparatively new element [4]. Since it is highly unstable, its atomic structure is quite difficult to study [4].

Oganesson Symbol

Its most stable isotope is 294Og, with a half-life of about 0.9 milliseconds, and it undergoes radioactive disintegration through α decay to form 290Lv (livermorium-290) [1, 2].

Where is it Found

Oganesson is not known to occur in nature and is artificially produced in laboratories [4].


Who discovered it: Russian nuclear physicist Yuri Oganessian is credited with the discovery of this element [2].

Origin of its Name: It is named after Yuri Oganessian himself, to recognize his research works in transactinide elements [1, 2].

When and How was Oganesson Discovered

A team of researchers, including scientists at the JINR (Joint Institute for Nuclear Research) in Dubna, worked in collaboration with those from the LLNL (Lawrence Livermore National Laboratory) in California to create the element 118 in October 2006 [1]. The scientists bombarded californium-249 atoms with calcium-48 ions using a cyclotron, producing an isotope Oganesson-294 with a half-life of 0.9 milliseconds and three neutrons [1]. The target atoms of californium were exposed to a total of 16×1018 calcium ions [1].

The discovery of Oganesson was confirmed by the IUPAC in 2015 through further experiments [5].

Oganesson Identification

Atomic number 118 [1]
CAS number 54144-19-3 [2]
Position in the periodic table Group name Group number Period Block
  Noble gas [1] 18 [1] 7 [2] p [2]

Location of Oganesson on the Periodic Table

Properties and Characteristics of Oganesson

Relative atomic mass 294 [2]

Physical Properties

Color Probably colorless [6]
Melting point/freezing point Unknown [2]
Boiling point Unknown [2]
Density Unknown [2]
State of matter at room temperature (solid/liquid/gas) Gas (expected) [1, 5]
Electrical conductivity Unknown [7]
Thermal (heat) conductivity Unknown [7]
Specific heat Unknown [2, 7]
Bulk modulus Unknown [2]
Shear modulus Unknown [2]
Young’s modulus Unknown [2]
Vapor pressure
– Temperature (K) 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400
– Pressure (Pa)

Chemical Properties

Oxidation state/Oxidation number [+1], [+2], [+4], [+6] [2]
Isotopes Isotope Mass Abundance Half-life Mode of decay
294Og 294.214 0.9 ms α

General PropertiesRelative atomic mass294 [2]

Physical Properties

ColorProbably colorless [6]Melting point/freezing pointUnknown [2]Boiling pointUnknown [2]DensityUnknown [2]State of matter at room temperature (solid/liquid/gas)Gas (expected) [1, 5]Electrical conductivityUnknown [7]Thermal (heat) conductivityUnknown [7]Specific heatUnknown [2, 7]Bulk modulusUnknown [2]Shear modulusUnknown [2]Young’s modulusUnknown [2]Vapor pressure – Temperature (K)40060080010001200140016001800200022002400– Pressure (Pa)———–

Chemical Properties

Oxidation statesUnknown [2]IsotopesIsotopeMassAbundanceHalf-lifeMode of decay 294Og294.214-0.9 msα

Atomic Data of Oganesson (Element 118)

Valence electrons 8
Quantum numbers 1S0  [7]
Electron configuration (noble gas configuration) [Rn] 5f146d107s27p6 [2]
Atomic structure
– Number of electrons 118 [5]
– Number of neutrons 176 [5]
– Number of protons 118 [5]
Radius of Atom
– Atomic radius Unknown [2]
– Covalent radius 1.57 Å [2]
Electronegativity (Pauling-scale) Unknown [2]
Electron affinity 5.403 kJ mol-1 [2]
Ionization energy (kJ mol-1) 1st 2nd 3rd 4th 5th 6th 7th 8th

Oganesson Atomic Structure (Bohr Model)

What is it used for

Oganesson is not a naturally occurring element and has only been synthesized in small quantities, making it useful only for basic scientific research [1, 5].

Possible Health Effects and Hazards

Because of its high radioactivity, Oganesson can be harmful to humans and other living organisms [5].

Interesting Facts

  • Oganesson was assigned a placeholder name “Ununoctium” with a symbol uuo, meaning one-one-eight in Latin, indicating its atomic number [3].
  • Oganesson is sometimes indicated by a 3D graphic representation of the island of stability, as it is one of heaviest elements showing the possibility of superheavy elements reaching stability at some point [2].


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