neon

Neon is a chemical element with the symbol Ne and atomic number 10. It is one of the noble gases, a group of inert, monoatomic gases in the periodic table. At room temperature neon is colorless, odorless, and tasteless. It is exceedingly unreactive and forms no stable compounds under normal conditions. Neon’s first ionization energy is about 2080 kJ/mol, reflecting its strong hold on its outer electrons. It is a lightweight gas with a boiling point of −246 °C and a density of about 0.9 g/L at standard conditions.

Neon occurs traceably in Earth’s atmosphere, comprising roughly 0.0018% by volume. It is primarily obtained as a byproduct of air separation and liquefaction processes used to produce nitrogen and oxygen. In the universe, neon is produced by nucleosynthesis in stars and is comparatively abundant in stellar environments, though it remains relatively scarce on Earth.

Historically, neon was discovered in 1898 by chemists Sir William Ramsay and Morris W. Travers while analyzing air components. The name neon comes from the Greek neos, meaning new.

In practical use, neon is best known for neon lighting. When subjected to an electric discharge, sealed tubes filled with neon emit a characteristic red–orange glow, widely used in signage and decorative lighting. Neon–helium or neon–argon mixtures are employed in certain light sources and lasers; notably, the helium–neon laser produces a stable red beam at 632.8 nm. Neon’s inertness and distinctive emissions underpin both its commercial applications and its role in scientific instrumentation.