Neon (Ne)

Neon (symbol Ne) is the chemical element with atomic number 10: a noble gas, with an atomic mass of 20.18 u. Discovered in 1898 (William Ramsay and Morris Travers).

Neon is a noble gas that forms no known chemical compounds. When an electric current passes through it, it gives off an intense red-orange glow that lent its name to illuminated signs. Though abundant in the Universe, it is rare on Earth and can only be obtained by distilling air. It plays a quiet but crucial role in making microchips.

Key facts

Atomic number: 10
Symbol: Ne
French name: Néon
Atomic mass: 20.18 u
Molar mass: 20.18 g/mol
Family: Noble gases
Position: period 2, group 18, p-block
State at 0 °C: Gas
Melting point: -248.6 °C
Boiling point: -246 °C
Density: 0.0009 g/cm³
First ionization energy: 2,081 kJ/mol
Atomic radius: 38 pm
Electron configuration: [He] 2s² 2p⁶
Abundance in Earth's crust: 0.005 ppm (73rd most abundant element)
Indicative price: 240 $/kg (order of magnitude)
Radioactive: no
Discovery: 1898, William Ramsay and Morris Travers

Origin of the name

From the Greek neos, new.

What does neon look like?

A colorless, odorless gas. In a discharge tube it emits a characteristic red-orange light.

Where is neon found?

Roughly the fifth most abundant element in the Universe, but only 18 ppm of Earth's atmosphere: too light and inert, most of it escaped when Earth formed.

Natural sources

Air (0.0018%)

How is neon produced?

Recovered as a by-product of liquid-air distillation in large oxygen plants, notably those serving steelworks. About 88,000 liters of air must be processed to obtain a single liter of neon.

Top producers

Ukraine
Russia
China

What is neon used for?

Red-orange signs and glowing tubes.
Gas mixtures for the excimer lasers used in chip lithography.
Helium-neon lasers (older barcode scanners, alignment).
Cryogenic fluid.
Indicator lamps and voltage testers.

In everyday life

The red glowing signs of bars and shop windows
The little light in a voltage-tester screwdriver
The chips in your phone, etched with neon-based lasers

Role in living things

No biological role: completely inert, it reacts with no molecule of life.

Hazards of neon

Non-toxic and non-flammable. The only dangers are suffocation after a massive leak in a closed room, or cold burns from liquid neon (−246 °C).

Cosmic origin

Supernovae: Forged in the cores of massive stars, then scattered when they explode.

History of neon

In 1898, British chemists William Ramsay and Morris Travers distilled liquefied air and, a few weeks after krypton, found a gas that glowed a brilliant red. Ramsay's 13-year-old son reportedly suggested the name novum (“new”), turned into neon from the Greek neos.

Did you know?

French engineer Georges Claude, founder of Air Liquide, unveiled the first neon tubes at the Grand Palais in Paris in 1910.
Only red-orange is “real” neon: blue, green or white signs use other gases (argon, mercury) or fluorescent powders.
In 2022, the war in Ukraine sparked fears of a shortage, since Ukraine supplied about half of the world's semiconductor-grade neon.

Isotopes of neon

Three stable isotopes, neon-20 being the most common. Their proportions vary with the gas's origin, offering clues to the history of Earth's mantle and of meteorites.

neon-20: 90.48% of natural neon, stable
neon-21: 0.27% of natural neon, stable. Made by cosmic rays inside rocks, it dates how long they have been exposed at the surface.
neon-22: 9.25% of natural neon, stable

Related elements

Same family (noble gases): Helium (He), Argon (Ar), Krypton (Kr), Xenon (Xe), Radon (Rn).

Same column (group 18): Helium (He), Argon (Ar), Krypton (Kr), Xenon (Xe), Radon (Rn), Oganesson (Og).