---
title: "Radon (Rn): Atomic Mass, Electron Configuration & Properties"
url: https://www.moldraw.com/elements/radon.html
description: "Radon (Rn), element 86: atomic mass [222], electron configuration [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁶, group 18, period 6, p-block noble gas. Melting and boiling point, density, electronegativity and shells."
lang: en
publisher: Scidart Academy
generated: 2026-11-03
---
86Rn[222]

# Radon (Rn) – element 86

Radon is a chemical element with the symbol **Rn** and atomic number **86**. It is a noble gas in group 18 (noble gases), period 6 of the periodic table (p-block), and is a gas at room temperature.

Radon (Rn) has atomic number 86, atomic mass [222] and electron configuration [Xe] 4f14 5d10 6s2 6p6.

[Download periodic table PDF](https://www.moldraw.com/printables/periodic-table.pdf)[Open interactive periodic table](https://www.moldraw.com/tools/free-chem-tools/interactive-periodic-table.html)

## Radon facts

| Symbol | Rn |
| --- | --- |
| Atomic number | 86 |
| Atomic mass | [222] |
| Category | noble gas |
| Group | group 18 (noble gases) |
| Period | 6 |
| Block | p-block |
| Phase at 20 °C | Gas |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 |
| Noble-gas notation | [Xe] 4f14 5d10 6s2 6p6 |
| Electrons per shell | 2, 8, 18, 32, 18, 8 |
| Valence electrons | 8 |

## Bohr model and shells

Radon has 86 electrons in 6 shells: 2, 8, 18, 32, 18, 8. Full configuration and noble-gas notation are in the table; work out any element or ion with the [electron configuration calculator](https://www.moldraw.com/tools/free-chem-tools/electron-configuration-calculator.html).

## Physical and atomic properties

| Melting point | 202 K (-71.1 °C) |
| --- | --- |
| Boiling point | 211.5 K (-61.6 °C) |
| Density | 9.73 g/L |
| Electronegativity (Pauling) | 2.2 |
| Electron affinity | -68 kJ/mol |
| Ionization energies | 1037 kJ/mol (1st) |
| Discovered by | Friedrich Ernst Dorn |

Use the atomic mass in the [molar mass calculator](https://www.moldraw.com/tools/free-chem-tools/molar-mass-calculator.html) for any formula containing Rn.

## Position in the periodic table

Tap any element to open its page.

## Frequently asked questions

### What is the atomic mass of radon?

The atomic mass of radon is [222] (mass number of its longest-lived isotope, since it has no stable isotope).

### What is the electron configuration of radon?

Radon has 86 electrons: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶, or [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁶ in noble-gas notation. Electrons per shell: 2, 8, 18, 32, 18, 8.

### How many valence electrons does radon have?

Radon has 8 valence electrons (group 18).

### Is radon a metal?

No. Radon is a nonmetal (noble gas).

### Where is radon on the periodic table?

Radon is in group 18 (noble gases), period 6, in the p-block.

Data: [Periodic-Table-JSON](https://github.com/Bowserinator/Periodic-Table-JSON) (CC BY-SA 3.0); standard atomic weights from IUPAC (abridged). Values in brackets are the mass number of the longest-lived isotope.