Neon is the chemical element with the symbol Ne and is used in bright advertising signs.
Neon has atomic number 10 and is a colorless, odorless noble gas at ordinary temperatures. It is chemically unreactive because its outer electron shell is complete. Although neon signs are often used as a general term for illuminated tubing, true neon produces a distinctive red-orange glow when an electric current passes through it.
British chemists William Ramsay and Morris Travers discovered neon in 1898 while separating gases from liquefied air. The name comes from the Greek word neos, meaning new. Neon is present in Earth’s atmosphere only in trace amounts and is obtained commercially during air separation.
Different gases create different colors in discharge tubes. Argon commonly produces a bluish or lavender glow, while mercury vapor can produce blue ultraviolet-rich light. Colored sign tubes may also use phosphor coatings, so not every glowing sign is a neon sign in the strict chemical sense.