Element 86
Radon (Rn)
Radon (Rn) is element 86 of the periodic table, a noble gas in period 6, group 18 (p-block) with an atomic mass of 222 and is a gas at standard conditions.
At a glance
- Atomic number
- 86
- Symbol
- Rn
- Atomic mass
- 222 u
- Category
- Noble gases
- Period
- 6
- Group
- 18
- Block
- p-block
- Phase at STP
- gas
Electron structure
- Electron configuration
- 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p6
- Shorthand configuration
- [Xe] 4f14 5d10 6s2 6p6
- Electrons per shell
- 2, 8, 18, 32, 18, 8
- Oxidation states
- 0, +2, +6
Physical properties
- Melting point
- 202 K
- Boiling point
- 211.3 K
- Density
- 0.00973 g/cm3
- Phase
- gas
Atomic properties
- Electronegativity (Pauling)
- 2.2
- Atomic radius
- 120 pm
- Covalent radius
- 150 pm
- Van der Waals radius
- 220 pm
- First ionization energy
- 1037 kJ/mol
- Electron affinity
- 0 kJ/mol
Notable isotopes
| Isotope | Mass | Abundance | Stability |
|---|---|---|---|
| Rn-222 | 222.01758 | — | Half-life 3.8 days |
Common uses
- Cancer treatment
- Earthquake prediction research
- Radiation studies
Discovery
- Year
- 1900
- Discovered by
- Friedrich Ernst Dorn
- Country
- Germany