Element 118 · Unknown properties
Oganesson (Og) — Element 118
Yuri Oganessian
Oganesson (Og) is a chemical element with unknown bulk chemical properties in Period 7, Group 18 of the periodic table with atomic number 118, standard atomic weight [294] u, and ground-state electron configuration [Rn] 5f¹⁴ 6d¹⁰ 7s² 7p⁶. At standard temperature and pressure it is classified as a short-lived synthetic nuclide with 0 valence electrons.
Research only — heaviest known element
What are the atomic properties and physical constants of Oganesson?
Reference constants compiled from IUPAC standard atomic weights, the NIST Atomic Spectra Database, and the CRC Handbook.
- Atomic number (Z)
- 118
- Standard atomic mass
- [294] u
- Chemical family
- Unknown properties
- Ground-state configuration
- [Rn] 5f¹⁴ 6d¹⁰ 7s² 7p⁶
- Electrons per shell
- 2, 8, 18, 32, 32, 18, 8
- Valence electrons
- 0
- Common ion charges / oxidation states
- —
- Phase at STP
- Synthetic
- Pauling electronegativity
- —
- First ionization energy
- —
- Atomic radius
- —
- Melting point
- —
- Boiling point
- —
- Discovery year
- 2006
- Table coordinate
- Period 7, Group 18
- Radioactivity
- Radioactive (no stable isotopes)
How are electrons arranged across Oganesson’s shells?
A neutral Oganesson atom contains 118 electrons distributed across 7 occupied principal energy shells ([Rn] 5f¹⁴ 6d¹⁰ 7s² 7p⁶). The table below compares Oganesson’s shell occupancy against each shell’s theoretical 2n² capacity.
| Principal Shell (n) | Spectroscopic Letter | Electrons in Og | Max Shell Capacity (2n²) |
|---|---|---|---|
| n = 1 | K | 2 e⁻ | 2 e⁻ |
| n = 2 | L | 8 e⁻ | 8 e⁻ |
| n = 3 | M | 18 e⁻ | 18 e⁻ |
| n = 4 | N | 32 e⁻ | 32 e⁻ |
| n = 5 | O | 32 e⁻ | 50 e⁻ |
| n = 6 | P | 18 e⁻ | 72 e⁻ |
| n = 7 | Q | 8 e⁻ | 98 e⁻ |
Frequently Asked Questions about Oganesson (Og)
What is the atomic mass and atomic number of Oganesson (Og)?
Oganesson (Og) has atomic number Z = 118 (118 protons in its nucleus) and an IUPAC standard atomic weight of [294] u. It sits in Period 7, Group 18 and is classified as an unknown properties.
What is the ground-state electron configuration of Oganesson?
The neutral ground-state electron configuration of Oganesson (Z = 118) is [Rn] 5f¹⁴ 6d¹⁰ 7s² 7p⁶. Across its 7 occupied principal shells (n = 1 to n = 7), the electrons per shell are 2, 8, 18, 32, 32, 18, 8, with 0 valence electrons participating in bonding.
What are the common ion charges and electronegativity of Oganesson?
Oganesson has no common simple monatomic ion charges under standard classroom conditions. Its Pauling electronegativity is — and its first ionization energy is —.
When was Oganesson discovered and what is it used for?
Oganesson was discovered in 2006 (Yuri Oganessian). Research only — heaviest known element
How does Oganesson compare to neighboring elements?
Other unknown properties elements: