The images of Las Vegas and the neon ‘dollar’ symbol reflect the use of the gas in neon lighting for advertising.

Fact Box

Uses

The largest use of neon is in making the ubiquitous ‘neon signs’ for advertising. In a vacuum discharge tube neon glows a reddish orange colour. Only the red signs actually contain pure neon. Others contain different gases to give different colours.

Neon is also used to make high-voltage indicators and switching gear, lightning arresters, diving equipment and lasers.

Liquid neon is an important cryogenic refrigerant. It has over 40 times more refrigerating capacity per unit volume than liquid helium, and more than 3 times that of liquid hydrogen.

History

In 1898, William Ramsay and Morris Travers at University College London isolated krypton gas by evaporating liquid argon. They had been expecting to find a lighter gas which would fit a niche above argon in the periodic table of the elements. They then repeated their experiment, this time allowing solid argon to evaporate slowly under reduced pressure and collected the gas which came off first. This time they were successful, and when they put a sample of the new gas into their atomic spectrometer it startled them by the brilliant red glow that we now associate with neon signs. Ramsay named the new gas neon, basing it on neos, the Greek word for new.