Neon is an unreactive gas present in small amounts in Earth's atmosphere. An electrical discharge through neon produces its characteristic red-orange glow. Signs displaying other colors often use different gases, making a familiar street scene a useful starting point for distinguishing elements through emitted light.
FROM ELEMENT TO APPLICATION
AN ELEMENT IN CONTEXT
Why does a neon sign need an electrical discharge to glow?
Neon gas in a discharge tube
FOLLOW THIS RELATIONSHIP
Supply a confined gas
A sign contains neon gas within a tube, giving the electrical system a defined medium rather than a solid glowing element symbol.
Explore the model (optional)
NeFORM → INTERACTION → CONSEQUENCE
Follow the explanation in either direction. These are authored steps, not a physical clock.
Optional: check your understanding
USE THE EXPLANATION
What tests the role of excitation?
Atomic identity, reference properties and structure models
INTERACTIVE 3D10 visible sites
An electron censusDrag to rotate · scroll or pinch to zoom
[He] 2s2 2p6. 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.
Ramsay and Travers searched separated fractions of liquefied air for gases missing from the emerging periodic pattern. In 1898, they isolated neon and recognized its striking discharge light. The laboratory discovery later became familiar in public lighting: Georges Claude demonstrated a neon lamp in Paris in 1910. A distinctive thus connected analytical evidence for an element with a new visual language in cities.
1898
Neon identified
Ramsay and Travers isolated a new gas and observed its distinctive emission.
1910
Public lamp demonstration
Georges Claude displayed a neon lamp at a Paris exhibition.
Neon occurs as a dilute component of Earth's atmosphere and is obtained during the separation of liquefied air. Its presence is easy to overlook because the gas is colourless under ordinary conditions. A glowing discharge tube therefore reveals a response to excitation, not the normal color of atmospheric neon.
Neon has low ordinary chemical reactivity, but an electrical discharge can make it emit conspicuous red-orange light. The light records changes in atomic energy states rather than combustion. Liquid neon also has cryogenic uses, illustrating that optical response, chemical reactivity, and behavior are separate properties.
Each section links its supporting references. Descriptions and diagrams were authored for this atlas. Source checks completed. Source checks dated 2026-09-06.
CITE THIS PAGE
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
24.56 K
at standard pressure unless noted
Boiling point in K
27.07 K
101.325 kPa
Density in g/cm³
0.0009 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
Not recorded
Pauling scale
First ionization energy in kJ/mol
2081 kJ/mol
gas-phase neutral atom, ground state
Covalent radius in pm
58 pm
single-bond covalent radius
Common oxidation states
0
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
0.005 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 2
Li 0.98 Pauling · Lithium
Electronegativity across period 2. Exact values.
Li
0.98
Be
1.57
B
2.04
C
2.55
N
3.04
O
3.44
F
3.98
Electronegativity down group 18
Kr 3 Pauling · Krypton
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.
