Xenon is an atmospheric noble gas used in intense light sources and spacecraft ion propulsion. It can also form compounds: xenon difluoride is used to etch silicon. These applications connect gas discharges, electrically accelerated atoms, and chemical reactions involving an element often described as unreactive.
FROM ELEMENT TO APPLICATION
AN ELEMENT IN CONTEXT
How does xenon push a spacecraft if it is not burned as fuel?
Ionized xenon propellant
FOLLOW THIS RELATIONSHIP
Supply electrical energy
The spacecraft’s power system provides electricity for ion propulsion. Xenon enters as propellant, serving a different role from the source of operating energy.
Explore the model (optional)
XeFORM → INTERACTION → CONSEQUENCE
Follow the explanation in either direction. These are authored steps, not a physical clock.
Optional: check your understanding
USE THE EXPLANATION
What would be missing from a tank of xenon considered as an ion-propulsion system?
Atomic identity, reference properties and structure models
INTERACTIVE 3D54 visible sites
An electron censusDrag to rotate · scroll or pinch to zoom
[Kr] 4d10 5s2 5p6. Grouping electrons by principal shell connects the neutral-atom configuration to periodic-table patterns.
What this representation means
A three-dimensional counting diagram. Dots are count markers, not measured electron positions; spherical placement and spacing are arbitrary. There are no electron trajectories here. Orbitals describe quantum states.
William Ramsay and Morris Travers separated xenon in 1898 while investigating fractions of liquefied air. Its revealed another member of the family then called inert gases. In 1962, Neil Bartlett demonstrated that xenon could form a compound, overturning the absolute version of that label. The historical lesson is precise: unusually low reactivity is an observed tendency, while complete chemical impossibility is a much stronger claim.
1898
Xenon separated
Ramsay and Travers identified xenon in liquid-air separations.
1962
Compound formation demonstrated
Bartlett challenged the supposed complete inertness of noble gases.
Xenon is a trace constituent of Earth's atmosphere and is separated from other gases during air processing. Its scarcity in a sample of air does not require a special xenon deposit. Industrial separation concentrates a dispersed gas until it can be supplied for lighting, research, or spacecraft systems.
Xenon is a monatomic noble gas under ordinary conditions and usually reacts reluctantly. Compounds such as xenon difluoride demonstrate that its chemistry is not empty. Ionization is a different process again: removing an creates a charged xenon particle without changing its atomic number into another element.
Each section links its supporting references. Descriptions and diagrams were authored for this atlas. Source checks completed. Source checks dated 2026-09-06.
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Family labels and the group-3 layout are teaching conventions. A table position does not establish an unknown bulk property. Electronic configurations refer to neutral atoms; ions and material environments require their own account.
Read each reference property together with its units, conditions and the reference information below.
Not yet recorded: electron affinity, second ionization energy, ground-state term symbol, van der waals radius, thermal conductivity, specific heat capacity, electrical resistivity, crystal structure, lattice parameter a, space group, abundance in seawater, abundance in the universe, annual production, supply-risk listing, hazard classification, biological role, cas registry number, pubchem cid, wikidata item. These families are declared and awaiting an ingestion run against the source each names; they are listed here rather than shown as empty rows.
Physical
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Phase at 20 °C
gas
293.15 K, 101.325 kPa
Melting point in K
161.4 K
at standard pressure unless noted
Boiling point in K
165.1 K
101.325 kPa
Density in g/cm³
0.00589 g/cm³
solids and liquids at 293 K; gases at 273 K and 101.325 kPa
Atomic and electronic
Intended reference: Pauling electronegativity scale · Widely tabulated; original in The Nature of the Chemical Bond
Electronegativity in Pauling
2.6 Pauling
Pauling scale
First ionization energy in kJ/mol
1170 kJ/mol
gas-phase neutral atom, ground state
Covalent radius in pm
140 pm
single-bond covalent radius
Common oxidation states
0, +2, +4, +6
states met in ordinary compounds; not exhaustive
Occurrence and identity
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Abundance in the crust in mg/kg
0.00003 mg/kg
upper continental crust, mass fraction
Has stable isotopes
Yesderived
Discovery year in CE
1898 CEderived
WHERE IT SITS AMONG ITS NEIGHBORS
Electronegativity across period 5
Xe 2.6 Pauling · Xenon
Electronegativity across period 5. Exact values.
Rb
0.82
Sr
0.95
Y
1.22
Zr
1.33
Nb
1.6
Mo
2.16
Tc
1.9
Ru
2.2
Rh
2.28
Pd
2.2
Ag
1.93
Cd
1.69
In
1.78
Sn
1.96
Sb
2.05
Te
2.1
I
2.66
Xe
2.6
Electronegativity down group 18
Xe 2.6 Pauling · Xenon
Electronegativity down group 18. Exact values.
Kr
3
Xe
2.6
The trend uses the same reference-property values as the periodic table. Elements with no recorded value are left out of the line rather than drawn at zero.
