Neon (Ne)

Neon is a noble gas with atomic number 10, in period 2 and group 18 of the periodic table. Its atomic mass is 20.1797 u and its electron configuration is [He] 2s² 2p⁶. Gas at 25 °C.

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Key facts

Atomic number	10
Atomic mass	20.1797 u
Category	Noble Gas
Period	2
Group	18
Block	p
Electron configuration	[He] 2s² 2p⁶
Electrons per shell	2, 8
Electronegativity (Pauling)	---
Oxidation states	---
State at 25 °C	Gas
Melting point	24.56 K−248.59 °C
Boiling point	27.07 K−246.08 °C
Density	0.9 g/L

Atomic properties

First ionization energy	21.565 eV
Electron affinity	0 kJ/mol
Atomic radius	38 pm
Covalent radius	58 pm
Van der Waals radius	154 pm
Common ions	---
Protons, neutrons, electrons	10, 10, 10

Physical and thermal properties

Molar volume	13.23 cm³/mol
Heat of fusion	0.34 kJ/mol
Heat of vaporization	1.75 kJ/mol
Specific heat	1030 J/(kg·K)
Thermal conductivity	0.0491 W/(m·K)
Thermal expansion	---
Mohs hardness	---
Young’s modulus	---
Crystal structure	Face-centered cubic
Magnetic type	Diamagnetic

Identification and history

CAS number	7440-01-9
Latin name	Neon
Discovered by	W. Ramsay & M. Travers · 1898
Named by	---

Natural isotopes

Isotope	Mass (u)	Abundance
²⁰Ne	19.99244	90.48 %
²¹Ne	20.993847	0.27 %
²²Ne	21.991385	9.25 %

Data checked against PubChem (NIH), IUPAC, the NIST Atomic Spectra Database and the IAEA (NUBASE and AME), the same data you see in the app.

A dash (---) means there is no reliable published measurement. The app never makes one up.

See Neon in the app

Orbital diagram with Hund’s rule, emission spectrum, shell model, every isotope, a real photo, and comparison with any other element. Free, no ads, works offline.

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