ne

Neon (symbol Ne) is a chemical element and a noble gas with atomic number 10. It is colorless, odorless, and tasteless, and it is extremely unreactive at room temperature. Neon is present only in trace amounts in Earth’s atmosphere and is primarily obtained by the fractional distillation of liquid air, produced as a by-product of industrial air separation. In the cosmos, neon is formed in stars through stellar fusion processes.

Neon was discovered in 1898 by Sir William Ramsay and Morris W. Travers, who isolated it from liquefied air. They named the element from the Greek neos, meaning new. Its most distinctive property is its glow: when energized in a vacuum discharge tube, neon emits a bright reddish-orange light. This property underpins its widespread use in signage and discharge lamps.

Neon is chemically inert and forms very few compounds under ordinary conditions. It has three stable isotopes—20Ne, 21Ne, and 22Ne—with 20Ne being the most abundant. On Earth, neon is extremely rare, comprising about 0.0018 percent by volume of the atmosphere (roughly 18 parts per million).

Uses of neon include bright signage, specialized lighting, and certain laser and optical applications such as helium–neon lasers that produce characteristic red light. Because neon is inert, it is non-toxic and non-flammable, but it can pose an asphyxiation risk in enclosed spaces if it displaces air. Neon remains one of the noble gases essential for both industrial lighting and various scientific applications.