Radon (Rn)
Radon is element 86, a noble gas in period 6, group 18 of the periodic table. At room temperature it is a gas.
Electron configuration [Xe] 4f14 5d10 6s2 6p6
Electrons per shell 2, 8, 18, 32, 18, 8
Radon data
| Atomic number | 86 |
|---|---|
| Symbol | Rn |
| Atomic mass | [222] (mass number of the longest-lived isotope) |
| Category | Noble gas |
| Group | 18 |
| Period | 6 |
| Block | p |
| State at 25 °C | gas |
| Melting point | 202 K (-71.1 °C) |
| Boiling point | 211 K (-62.1 °C) |
| Density | 0.00973 g/cm³ (9.73 g/L) |
| Electronegativity (Pauling) | — |
| Atomic radius | 145 pm |
| 1st ionization energy | 1037 kJ/mol |
| Electron affinity | — |
| Oxidation states | +2 |
| Common ion charge | 0 |
| Discovered | 1900 |
Orbital diagram
Each box is one orbital holding up to two electrons of opposite spin. Following Hund’s rule, electrons spread out singly across a subshell before pairing.
Work through radon’s configuration and its ions →
Where radon sits
Radon belongs to the noble gases. To use its mass in a calculation, try the molar mass calculator.
Radon FAQ
What is the electron configuration of radon?
Radon (Z = 86) has the configuration 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d10 6s2 6p6. In noble-gas shorthand that is [Xe] 4f14 5d10 6s2 6p6.
How many valence electrons does radon have?
8 (full outer shell).
What is the atomic mass of radon?
Radon has no stable isotopes. Its most stable known isotope has mass number 222, so tables list [222].
Is radon a metal?
No. Radon is a noble gas.
What is the charge of a radon ion?
Radon most commonly forms no ions.