Chemical element · Atomic number 86
Radon
Radon in the periodic table: atomic number 86, electron configuration, atomic mass, physical data, oxidation states, media credit and visible sources.
Noble gas
gaseous
[222.01758] u
Generated illustrationGenerated illustration, Quanta Study. Not a photograph of a sample.
Generated illustration of Radon; the image does not show a sample of the element.
Highly radioactive element; no freely licensed photograph of a sample is available.
Code-native illustration with the Quanta Study mark inside the image; not a photograph, no AI model involved.
Atomic classification
Shell occupancy
Radon in the Bohr shell model
This shows the electron distribution of the neutral atom in a simplified shell model.
- K · n=1
- 2 electrons
- L · n=2
- 8 electrons
- M · n=3
- 18 electrons
- N · n=4
- 32 electrons
- O · n=5
- 18 electrons
- P · n=6
- 8 electrons
- Electron configuration
- [Xe]6s2 4f14 5d10 6p6
- Electrons per shell
- 2 · 8 · 18 · 32 · 18 · 8
- Group
- 18
- Period
- 6
- Block
- P
- Element category
- Noble gas
Physical and chemical properties
- Atomic mass
- [222.01758] u
- Standard state
- gaseous
- Density
- 0.00973 g/cm³
- Melting point
- 202 K
- Boiling point
- 211.45 K
- Electronegativity
- not reported
- First ionisation energy
- 10.745 eV
- Oxidation states
- 0
- Discovery
- 1900
Safety and periodic classification
Safety
Safe handling cannot be inferred from Radon's position in the periodic table alone. Laboratory, classroom and disposal decisions must follow the documentation for the exact material and its safety data sheet.
Position and comparison
Radon is in period 6, group 18 and the P block. Its direct neighbours by atomic number are Astatine and Francium. The snapshot does not report a Pauling electronegativity. Periodic trends are compared only through the separately sourced neighbouring values.
Sources and scope
PubChem attributes element data to sources including IUPAC, NIST and IAEA. Quanta stores the referenced snapshot locally and leaves unknown values unavailable.
Where Radon sits among the 118 elements
The table compares the reported values for Radon with every other element that carries the same value in the snapshot. A rank is not a judgement, it is orientation: it says how unusual this value is across the periodic table.
| Value | Radon | Position in the data set |
|---|---|---|
| Melting point | 202 K | Rank 93 of 103 elements with a reported value. Highest: Carbon. |
| Boiling point | 211.45 K | Rank 84 of 93 elements with a reported value. Highest: Rhenium. |
| Density | 0.01 g/cm³ | Rank 86 of 96 elements with a reported value. Highest: Osmium. |
| Ionisation energy | 10.745 eV | Rank 13 of 102 elements with a reported value. Highest: Helium. |
All values and ranks come from the PubChem Periodic Table snapshot, retrieved on 2026-07-15. Elements without a reported value are excluded, so the population differs per row.
The neighbours of Radon in the periodic table
- Place in the table
- Group 18, period 6, P block. Classified as noble gas, gaseous at standard conditions.
- Direct neighbours
- Atomic number 86. Preceded by Astatine, followed by Francium.
- Same group
- Same number of outer electrons, and therefore similar reactivity to Helium, Neon, Argon, Krypton, Xenon, Oganesson.
- Discovery
- Recorded in the snapshot as: 1900. Who, where and under what circumstances is not part of that record, so this page carries the sourced year and no discovery narrative.
- Oxidation states
- 0. They follow from the electron configuration [Xe]6s2 4f14 5d10 6p6 and indicate which compounds to expect.
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