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10Ne20.180
Noble Gasesgas at STPP-block

Neon

Group: 18Period: 2Standard Atomic Weight: 20.180 u

Why is Neon in this position?

Understanding the scientific rationale behind Neon's position in the periodic table:

Group Assignment
Group 18

Belongs to Group 18 because it possesses a complete octet of 8 valence electrons (2s² 2p⁶).

Period Assignment
Period 2

Belongs to Period 2 because its valence electrons fill principal quantum level n=2.

Orbital Block
P-block

Belongs to the p-block because its valence subshell is a completely filled 2p orbital.

Chemical Category
Noble Gases

Classified as a noble gas due to its complete chemical inertness and zero electronegativity.

Atomic Structure & Bohr Shell Model

Shell Distribution: [2, 8]

Bohr Atomic Shell Model(2, 8)

Hover or tap any shell orbit ring to inspect electron counts and 2n² capacities.

10 Protons (p⁺)10 Neutrons (n⁰)
KShell K: Electron 1 of 2Shell K: Electron 2 of 2LShell L: Electron 1 of 8Shell L: Electron 2 of 8Shell L: Electron 3 of 8Shell L: Electron 4 of 8Shell L: Electron 5 of 8Shell L: Electron 6 of 8Shell L: Electron 7 of 8Shell L: Electron 8 of 8NeZ = 10

Educational Note: This Niels Bohr planetary model visually illustrates principal quantum energy shells ($n=1, 2, 3\dots$) and electron counts. In modern quantum mechanics (Schrödinger model), electrons do not orbit in fixed circular planetary tracks, but exist as 3D probability clouds (orbitals: $s, p, d, f$) governed by the Heisenberg uncertainty principle.

Electron Shell Filling Breakdown

Shell K (n=1):2 / 2 electrons (100%)
Shell L (n=2):8 / 8 electrons (100%)
Aufbau Electron Configuration
1s² 2s² 2p⁶

Neutral ground state configuration. Valence electrons: 8.

Atomic & Quantum Properties

Electronegativity (Pauling)Not available
1st Ionization Energy2080.7 kJ/mol
Electron Affinity0 kJ/mol
Atomic Radius (empirical)38 pm
Common Oxidation States0
Crystal StructureFCC

Physical & Thermal Properties

Density at STP0.00090 g/cm³
Melting Point-248.59 °C (24.56 K)
Boiling Point-246.05 °C (27.1 K)
Magnetic OrderingDiamagnetic
Discovery Year1898
Discovered BySir William Ramsay & Morris Travers

Real-World Uses, Occurrence & Compounds

Major Industrial & Everyday Uses
  • Vibrant advertising neon sign illumination
  • High-voltage circuit testers and lightning arresters
  • Helium-Neon (He-Ne) gas lasers used in barcode scanning and optical physics
  • Economical cryogenic refrigerant with 40x the cooling capacity of liquid helium
Occurrence in Nature

Abundant in stars and galaxies, but trace in Earth's atmosphere (18.2 parts per million by volume).

Etymology & Name Origin

From Greek 'neos' meaning new

Important Chemical Compounds
None (no stable chemical compounds known to exist)
Interesting Chemical Facts
  • True neon signs only glow reddish-orange; signs glowing in other colors use argon, mercury vapor, or phosphor coatings.
  • Liquid neon is a more compact cryogenic refrigerant than liquid helium, requiring smaller storage vessels.
  • Neon is formed inside giant stars during the carbon-burning stage of stellar evolution.
Safety & Handling Note

Chemically inert and non-toxic, but acts as a rapid asphyxiant in closed spaces.