Periodic table › Neon
1. Identity and classification
Colorless, odorless, tasteless monatomic gas; emits characteristic vivid glow in high-voltage plasma tubes
- Name and symbol
- Neon (Neon) · Ne
- Atomic number
- 10
- Relative atomic weight / mass number
- 20.180 ± 0.001
- Group · period · block
- 18 · 2 · p
- Category
- Noble Gas
- State near room temperature
- Gas
- Stable isotopes
- At least one stable isotope
- CAS number
- 7440-01-9
Square brackets [A] indicate a representative isotope mass number, not an average atomic weight. Neutron counts differ between isotopes.
2. Atomic structure and electron configuration
- Protons · electrons in a neutral atom
- 10 · 10
- Neutrons in reference isotope
- 10 (20Ne)
- Full electron configuration
1s² 2s² 2p⁶- Abbreviated configuration
[He]2s² 2p⁶- Electrons per shell
- 2, 8
- Listed oxidation states
- 0
- Electronegativity
- Not established
- First ionization energy
- 2080.706 kJ/mol · 21.565 eV
- Electron affinity
- Not established
- Covalent radius
- 58 pm
- van der Waals radius
- 154 pm
Configurations of superheavy elements may include theoretical predictions. Different definitions of atomic radius are not interchangeable.
3. Physical and thermal properties
- Density
- 0.0008999 g/cm³
- Melting point
- 24.56 K · -248.59 °C · -415.462 °F
- Boiling point
- 27.07 K · -246.08 °C · -410.944 °F
- Crystal structure
- FCC
- Specific heat
- 1.03 J/(g·K)
- Thermal conductivity
- 0.0491 W/(m·K)
- Enthalpy of fusion
- 0.335 kJ/mol
- Enthalpy of vaporization
- 1.71 kJ/mol
- Magnetic ordering
- Diamagnetic
- Mohs hardness
- Not established
- Speed of sound
- 435 m/s
Density and structure depend on temperature, pressure and allotrope. 25°C is a room-temperature reference, not STP. Unestablished values are not zero.
4. Chemical behavior and compounds
Closed valence shells explain low reactivity; xenon and krypton can form compounds under suitable conditions.
Selected compounds: Monatomic gas — no stable compounds at STP
Reaction reference
No ordinary reaction with air.
No ordinary reaction with water.
5. Isotopes
| Isotope | Status | Natural abundance | Half-life |
|---|---|---|---|
| 20Ne | Stable | 90.48% | Stable |
| 21Ne | Stable | 0.27% | Stable |
| 22Ne | Stable | 9.25% | Stable |
Half-life units: s seconds, m minutes, h hours, d days, Y years. A dash means no natural-abundance value is given, not zero. Listed records are selected ground states; metastable states are distinct.
6. Discovery and occurrence
- Discovery
- 1898 CE
- Scientists associated with discovery
- William Ramsay & Morris Travers
- Location
- United Kingdom (London)
- Origin
- Natural
- Listed crustal abundance
- Not established
Minerals and naming reference
Fractional distillation of liquid air (0.0018% of atmosphere)
Named from scientific/historical roots associated with Neon (Ne), discovered or characterized by William Ramsay & Morris Travers.
7. Applications
High-voltage neon indicator signs, helium-neon (He-Ne) lasers, cryogenic refrigerant, deep-sea diving gas mixtures
Detailed applications by field
- everyday
- High-voltage neon indicator signs, helium-neon (He-Ne) lasers, cryogenic refrigerant, deep-sea diving gas mixtures
- industry
- Used in noble gas processing, specialized alloys, and chemical manufacturing (High-voltage neon indicator signs, helium-neon (He-Ne) lasers, cryogenic refrigerant, deep-sea diving gas mixtures).
- electronics
- Applied in electronic components, semiconductors, or functional coatings where Neon's electronic structure ([He] 2s² 2p⁶) provides target conductivity.
- medicine
- Diagnostic imaging, biomedical instrumentation, or pharmaceutical synthesis research.
- energy
- Utilized in power generation, battery materials, catalysts, or nuclear technology involving Neon.
- aerospace
- High-performance materials, structural alloys, or space instrumentation utilizing Neon.
- agriculture
- Soil geochemistry analysis, trace micronutrient research, or analytical environmental monitoring.
- science
- Spectroscopic standard, crystallography, and quantum chemistry studies of Period 2 p-block elements.
8. Biological role and safety
Hazard depends on the isotope, chemical form, dose and exposure route.
Elemental substances, ions, compounds and radioisotopes can have different health effects. This is an educational reference; laboratory work requires the material safety data sheet and trained supervision.
Biological role reference
Classified as non-essential in human and biological systems.