What is the electron configuration of xenon?

Xenon (Xe, Z=54) has the ground-state electron configuration 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶. In condensed noble-gas notation this is written [Kr] 4d¹⁰ 5s² 5p⁶.

What does [Xe] mean in electron configurations?

[Xe] is the noble-gas shorthand representing xenon's 54-electron filled core (1s² through 5p⁶). For example, cesium (Z=55) is written [Xe] 6s¹, and lanthanum (Z=57) is [Xe] 5d¹ 6s². All lanthanides and actinides build on the [Xe] core.

Why is xenon mostly chemically inert?

Xenon has a completely filled outer shell (5s² 5p⁶) with no unpaired electrons and no low-energy empty orbitals. Its first ionization energy (1170.4 kJ/mol) is high, but lower than krypton's, which is why xenon — unlike lighter noble gases — can form stable fluorides (XeF₂, XeF₄, XeF₆) under appropriate conditions.

How many valence electrons does xenon have?

Xenon has 8 valence electrons (2 in 5s and 6 in 5p), completing the octet. The filled 4d subshell is a core subshell, not considered valence in standard chemistry.

What block and period is xenon in?

Xenon is in Period 5, Group 18 (noble gases), and belongs to the p-block of the periodic table. It sits between iodine (Z=53) and cesium (Z=55).

Which elements use [Xe] as their noble-gas core?

All elements from cesium (Z=55) through radon (Z=86) use [Xe] in their condensed configurations. This includes barium, all 14 lanthanides (La–Lu), hafnium through mercury (the third-row transition metals), and thallium through radon in the p-block.

Does xenon form real chemical compounds?

Yes. Xenon forms a range of stable fluorides (XeF₂, XeF₄, XeF₆) and oxides (XeO₃, XeO₄) under ordinary laboratory conditions. XeF₂ is commercially available. This reactivity — unique among the lighter noble gases — arises because xenon's outer electrons are more polarizable due to the larger atomic radius and lower ionization energy compared to argon or krypton.

Xenon Electron Configuration

Reference for xenon's electron configuration (1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ or [Kr] 4d¹⁰ 5s² 5p⁶), orbital box diagram, quantum numbers, and its role as noble-gas core [Xe] for lanthanides and beyond.

Z = 54 Xe Xenon

Xenon — Electron Configuration

Atomic number 54 · Noble gas · Period 5, Group 18 · p-block

[Kr] 4d¹⁰ 5s² 5p⁶ 54 electrons 8 valence e⁻ Noble-gas core [Xe]

Subshell Breakdown

Subshell	Type	Electrons	Max Capacity	Notation
1s	s orbital, shell n=1	2	2	1s²
2s	s orbital, shell n=2	2	2	2s²
2p	p orbitals, shell n=2	6	6	2p⁶
3s	s orbital, shell n=3	2	2	3s²
3p	p orbitals, shell n=3	6	6	3p⁶
3d	d orbitals, shell n=3	10	10	3d¹⁰
4s	s orbital, shell n=4	2	2	4s²
4p	p orbitals, shell n=4	6	6	4p⁶
4d	d orbitals, shell n=4	10	10	4d¹⁰
5s	s orbital, shell n=5	2	2	5s²
5p	p orbitals, shell n=5 (valence)	6	6	5p⁶
Total		54

Full Configuration

1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶

All 11 subshells written explicitly.

Noble-Gas Shorthand

[Kr] 4d¹⁰ 5s² 5p⁶

[Kr] = 1s² … 4p⁶ (krypton's filled 36-electron core).

Used as Core ([Xe])

[Xe] = 1s²…5p⁶

Shorthand for Cs, Ba, lanthanides, and actinides.

Shell Fill Summary

Shell 1 (n=1) — 1s² 2 / 2 electrons (100%)

Shell 2 (n=2) — 2s² 2p⁶ 8 / 8 electrons (100%)

Shell 3 (n=3) — 3s² 3p⁶ 3d¹⁰ 18 / 18 electrons (100%)

Shell 4 (n=4) — 4s² 4p⁶ 4d¹⁰ 18 / 32 electrons (56%)

Shell 5 (n=5) — 5s² 5p⁶ 8 / 50 electrons (16%)

Shell 4 can hold up to 32 electrons (4s + 4p + 4d + 4f). Xenon fills only 18 of those 32 slots — the 4f subshell is empty. Shell 5 can hold 50 electrons but xenon fills only 8 (5s + 5p). The next electrons (in cesium) jump to 6s.

Elements That Use [Xe] as Their Core

Element	Z	Configuration
Cesium (Cs)	55	[Xe] 6s¹
Barium (Ba)	56	[Xe] 6s²
Lanthanum (La)	57	[Xe] 5d¹ 6s²
Cerium (Ce)	58	[Xe] 4f¹ 5d¹ 6s²
Gadolinium (Gd)	64	[Xe] 4f⁷ 5d¹ 6s²
Gold (Au)	79	[Xe] 4f¹⁴ 5d¹⁰ 6s¹
Radon (Rn)	86	[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁶

Orbital Box Diagram

Each box represents one orbital. Up arrow = spin +½, down arrow = spin −½. All xenon orbitals are fully paired (diamagnetic).

2 e⁻ — filled

6 e⁻ — filled

2 e⁻ — filled

6 e⁻ — filled

10 e⁻ — filled

2 e⁻ — filled

6 e⁻ — filled

10 e⁻ — filled

2 e⁻ — filled (valence)

6 e⁻ — filled (valence)

Every orbital in xenon holds two electrons with opposite spins (+½ and −½). There are no unpaired electrons — xenon is diamagnetic. The highlighted 5s and 5p subshells are the valence orbitals.

Quantum Numbers — Valence Shell (5s² 5p⁶)

e⁻ #	n	l	mₗ	mₛ	Subshell
37	5	0	0	+½	5s
38	5	0	0	−½	5s
49	5	1	-1	+½	5p
50	5	1	-1	−½	5p
51	5	1	0	+½	5p
52	5	1	0	−½	5p
53	5	1	1	+½	5p
54	5	1	1	−½	5p

n = principal quantum number; l = azimuthal (l=0 → s, l=1 → p); mₗ = magnetic; mₛ = spin. Electrons 1–36 and 39–48 fill the remaining inner subshells through 4d with analogous quantum numbers.

Summary

Xenon (Xe) is element 54 — a Period 5, Group 18 noble gas with the ground-state configuration 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶. All 54 electrons are fully paired across eleven filled subshells, giving xenon exceptional chemical stability and a first ionization energy of 1170.4 kJ/mol. The [Xe] shorthand is used as the noble-gas core for cesium, barium, and all lanthanide and actinide elements. This tool shows the full configuration table, orbital box diagram, quantum numbers for the 5s and 5p valence electrons, and key element facts.

How it works

The Aufbau principle fills subshells from lowest to highest energy: 1s → 2s → 2p → 3s → 3p → 4s → 3d → 4p → 5s → 4d → 5p.
Xenon's 54 electrons completely fill eleven subshells across five principal shells.
The filled 5p subshell (6 electrons across three orbitals) is the outermost and closes xenon's valence shell.
With no unpaired electrons and a complete outer shell, xenon has zero chemical valence under ordinary conditions.
In noble-gas notation, [Xe] replaces the filled 54-electron core for all elements with Z ≥ 55.
Use the tabs below to explore the configuration table, orbital diagram, and element properties.

Use cases

Quick reference for chemistry homework or exams on noble-gas and Period 5 configurations.
Understand why xenon forms a small number of stable fluoride compounds while still being classified as a noble gas.
Use [Xe] shorthand correctly when writing configurations for cesium through radon.
Visualize the fully paired 5p subshell that closes Period 5.
Compare xenon to argon ([Ar]) and krypton ([Kr]) as noble-gas cores.
Teaching aid for Aufbau principle, Hund's rule, and Pauli exclusion principle with a heavier element.
Reference quantum numbers for xenon's valence electrons in advanced chemistry courses.

Frequently Asked Questions

Last updated: 2026-09-30 · Reviewed by Nham Vu

Xenon Electron Configuration

Xenon — Electron Configuration

Subshell Breakdown

Shell Fill Summary

Elements That Use [Xe] as Their Core

Orbital Box Diagram

Quantum Numbers — Valence Shell (5s² 5p⁶)

Identity

Physical Properties

Electronic Properties

Context & Uses

Summary

How it works

Use cases

Frequently Asked Questions

Xenon Electron Configuration

Use the Xenon Electron Configuration

Xenon — Electron Configuration

Subshell Breakdown

Shell Fill Summary

Elements That Use [Xe] as Their Core

Orbital Box Diagram

Quantum Numbers — Valence Shell (5s² 5p⁶)

Identity

Physical Properties

Electronic Properties

Context & Uses

Summary

How it works

Use cases

Frequently Asked Questions