“Mel’s Diner,” “Lovelace Motel, no vacancies,” and “Blue Moon espresso coffee”
For night-time road warriors, the steady red of a neon sign “Open 24 hours” broadcasts the hope of coffee, warmth – maybe even a slice of pie.
Neon is a colorless element, but when placed in a glass tube and charged with an electrical current, the gas emits a brilliant red-orange glow that is familiar as the neon lights used for outdoor advertisements and more recently as architectural embellishments. The glowing tube lights are often collectively referred to as neon lights, but colors other than the “liquid fire” red are produced by other gases included in the tubes.
Neon was discovered in 1898 by the Scottish chemist Sir William Ramsey and his student, Morris Travers, as they explored the chemistry of gases. They had chilled down a sample of air to turn it into a liquid and were very gently warming up the sample again, capturing and isolating each different substance as it passed back into the gas phase. They identified nitrogen, oxygen, the Nobel gases argon, krypton, and xenon, and another gas, which they called Neon, meaning “new.”
Although neon is the fifth most abundant element by mass in the universe, it is relatively rare on earth. Neon is classified as an inert gas, meaning it doesn’t form chemical compounds with other elements, it tends to escape through the atmosphere. Neon’s light mass and high vapor pressure at low temperatures make it rise in the atmosphere; a balloon filled with neon will rise in the air, although not as quickly as the lighter element helium. Data collected by the Galileo spacecraft indicate that even Jupiter, with its substantially stronger gravity, has an atmosphere nearly devoid of neon.
More information about neon can be found at http://www.chemicool.com/elements/neon.html