Element 86 · Radon (Rn)

Radon Bohr model: diagram and electrons per shell

The radon Bohr model shows a radon atom (Rn) as a small nucleus with its electrons circling it in 6 shells: 2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 18 in shell O and 8 in shell P. This page has a rotating 3D radon Bohr model, a flat diagram, a table of the electrons in each shell and the steps to draw it yourself.

Rotate the radon Bohr model in 3D

Drag to orbit, scroll to zoom.

This is a Bohr model of radon (Rn), a simplified picture of a single radon atom. Its nucleus holds 86 protons, and a neutral radon atom has 86 electrons, arranged around it in 6 shells (2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 18 in shell O and 8 in shell P).

Rn K · 21s² L · 82s² 2p⁶ M · 183s² 3p⁶ 3d¹⁰ N · 324s² 4p⁶ 4d¹⁰ 4f¹⁴ O · 185s² 5p⁶ 5d¹⁰ P · 86s² 6p⁶

Radon Bohr model diagram

Bohr model diagram of radon: a nucleus of 86 protons with 86 electrons on 6 shells, 2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 18 in shell O and 8 in shell P, each ring labelled with its shell letter. — The radon Bohr model drawn flat: each ring is a shell, labelled with its letter, and every dot is an electron (2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 18 in shell O and 8 in shell P).

Radon electrons per shell

A neutral radon atom has 86 electrons, one for each of its 86 protons. They fill the shells from the nucleus outwards: 2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 18 in shell O and 8 in shell P.

Electrons in each shell of the radon Bohr model
Shell	Shell number (n)	Electrons	Most it can hold (2n²)	Subshells
K	1	2	2	1s²
L	2	8	8	2s² 2p⁶
M	3	18	18	3s² 3p⁶ 3d¹⁰
N	4	32	32	4s² 4p⁶ 4d¹⁰ 4f¹⁴
O	5	18	50	5s² 5p⁶ 5d¹⁰
P	6	8	72	6s² 6p⁶

How the radon Bohr model builds up, shell by shell

Watch the radon Bohr model come together: the nucleus first, then each shell in turn, from the innermost outwards, with its electrons joining the ring. The legend names every shell and counts its electrons, so you can read off the arrangement (2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 18 in shell O and 8 in shell P) as it forms.

Animation of the radon Bohr model being built: a nucleus of 86 protons appears first, then each shell grows in around it and takes its electrons, giving 86 electrons on 6 shells (2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 18 in shell O and 8 in shell P). — The radon Bohr model built up in six seconds: the nucleus first, then each shell with its electrons, ending with 2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 18 in shell O and 8 in shell P. Protons are red, neutrons yellow and electrons blue.

How to draw the radon Bohr model

Find the atomic number. Radon has atomic number 86, so a neutral atom has 86 protons and 86 electrons.
Draw the nucleus. Put a circle in the centre and write Rn in it. The 86 protons sit there with the neutrons.
Draw the shells. Sketch 6 shells as rings around the nucleus. A shell holds at most 2n² electrons: 2 in the first, 8 in the second, 18 in the third and 32 in the fourth.
Place the electrons. Fill from the inside out: 2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 18 in shell O and 8 in shell P.
Check the total. 2 + 8 + 18 + 32 + 18 + 8 = 86, the atomic number, so every electron is accounted for.

Atomic data for the radon Bohr model

The numbers behind the radon Bohr model, grouped by topic. Radii are in picometres (pm) and energies in kilojoules per mole (kJ/mol).

Identity

Symbol: Rn
Atomic number: 86
Atomic mass: [222] u
Family: Noble Gases
Position: group 18, period 6
Block: p-block

Electron configuration

Full: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶
Shorthand: [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁶
Electrons per shell: 2, 8, 18, 32, 18, 8
Outer-shell electrons: 8 in shell P

Ionisation energies

I₁: 1037

Energy to remove each electron in turn (kJ/mol). A sharp jump means the next electron comes from an inner shell.

Atomic radii

Calculated (pm): 120
Covalent (pm): 142
Van der Waals (pm): 220

Electronegativity and electron affinity

Electronegativity (Pauling): 2.2
Electron affinity (kJ/mol): -68

Physical properties, abundance and history of radon

Bulk properties of radon, how common it is, who discovered it and some of its compounds.

Physical properties

Phase at room conditions: Gas
Appearance: Colorless gas, occasionally glows green or red in discharge tubes
Melting point: -71.15°C (202 K)
Boiling point: -61.65°C (211.5 K)
Density: 0.00973 g/cm³
Thermal conductivity (W/m·K): 0.004
Specific heat (J/g·K): 0.094
Heat of vaporisation (kJ/mol): 18.1

Abundance

Earth's crust (mg/kg): 0
Oceans (mg/L): 0

Discovery

Discovered by: Friedrich Ernst Dorn
Year: 1900

Common compounds

Radon Rn
Radon-222 Rn
Radon-220 Rn
Actinon Rn
Water radon H2ORn
(~226~Rn)Radon Rn
Radon-218 Rn
Radon-228 Rn

Compounds listed in the PubChem database.

Main isotopes of radon

Isotopes of radon share the same 86 protons but differ in neutrons. Natural isotopes come first, then the longest-lived others.

Main isotopes of radon: mass number, abundance, half-life and decay
Mass number	Natural abundance	Half-life	Decay
209	–	28.8 min	β⁺, α
210	–	2.4 h	α, β⁺
211	–	14.6 h	β⁺, α
221	–	25.7 min	β⁻, α
222	–	3.821 d	α
224	–	107 min	β⁻

α = alpha decay, β⁻ = beta-minus, β⁺ = beta-plus, EC = electron capture, SF = spontaneous fission, p / n = proton / neutron emission.

More about radon

Radon on the periodic table – properties, isotopes, uses and the full radon page.
Noble Gases – all noble gas elements and their trends.
Bohr model of every element – the Bohr model of all 118 elements.