Oganesson
[Rn] 5f¹⁴ 6d¹⁰ 7s² 7p⁶ · 2 · 8 · 18 · 32 · 32 · 18 · 8
The last box of the periodic table. Oganesson sits under the noble gases, but calculations say it should be a solid at room temperature and noticeably reactive — relativistic effects demolishing the inertness one would expect.
3D model
Bohr model: nucleus and electron shells from the real configuration. Valence electrons are highlighted.
Drag to rotate, scroll to zoom
Atomic properties
- Atomic number
- 118
- Atomic mass
- 294 а.е.м. ≈
- Electron configuration
- [Rn] 5f¹⁴ 6d¹⁰ 7s² 7p⁶
- Electrons per shell
- 2 · 8 · 18 · 32 · 32 · 18 · 8
- Block
- p-block
- Group
- Noble gases
- Period
- 7
- Electronegativity (Pauling)
- no data
- Electronegativity (Allen)
- no data
- Atomic radius
- no data
- Covalent radius
- 157 pm
- Van der Waals radius
- no data
- Ionisation energy 1
- 860.1 kJ/mol ≈
- Electron affinity
- 5.4 kJ/mol ≈
- Common oxidation states
- 0
- Oxidation states
- -1, 0, +1, +2, +4, +6
Physical properties
- State at 25 °C
- solid
- Density
- 6.6 g/cm³ ≈
- Melting point
- 325 K · 51.9 °C ≈
- Boiling point
- 450 K · 176.9 °C ≈
- Speed of sound
- no data
Thermal properties
- Heat of fusion
- 23.5 kJ/mol ≈
- Heat of vaporisation
- 19.4 kJ/mol ≈
- Specific heat capacity
- no data
- Thermal conductivity
- no data
Mechanical properties
- Young's modulus
- no data
- Shear modulus
- no data
- Bulk modulus
- no data
- Poisson ratio
- no data
- Mohs hardness
- no data
- Brinell hardness
- no data
Electrical and magnetic properties
- Electrical resistivity
- no data
- Magnetic ordering
- no data
- Curie point
- no data
- Néel point
- no data
- Superconducting point
- no data
Crystal structure
- Crystal structure
- face-centred cubic (fcc) ≈
- Lattice constants
- no data
Abundance
- In the crust
- 0 mg/kg
- In the ocean
- 0 mg/L
- In the universe
- 0 mg/kg
- In the human body
- 0 mg/kg
Isotopes
| Isotope | Abundance | Half-life | Decay mode |
|---|---|---|---|
| 294Og | — | 0.001 s | α |
Oganesson-294, half-life about 0.7 milliseconds, is the only isotope reliably observed.
Discovery
- Year of discovery
- 2002
- Discovered by
- JINR and Lawrence Livermore
- Where
- Dubna, Russia
- Origin of the name
- after Yuri Oganessian, the second element named for a living scientist
History
JINR and Livermore synthesised element 118 in 2002 by bombarding californium-249 with calcium-48 ions. The name was confirmed in 2016, honouring Yuri Oganessian, who leads Dubna's superheavy element programme.
Where it occurs
Absent from nature.
How it is produced
By nuclear fusion: californium-249 bombarded with calcium-48 ions. About five atoms have been registered in all of history.
Role in living things
No biological role.
Safety
Only single atoms are ever handled.
Uses
Fundamental research into the limits of the periodic system
Curiosities
- Oganesson is the second element in history named after a living scientist, after seaborgium.
- About five atoms of oganesson have ever been made — fewer than of any other element.
- Relativistic calculations predict oganesson is a solid and behaves nothing like a noble gas.
- Oganesson closes period seven; starting period eight needs element 119, whose synthesis has so far failed.
- Oganesson's electron shell is so smeared by relativistic effects that the very notion of an orbital loses its usual meaning.