December 22, 2014
Image of Neon

Why are we presenting neon for Christmas week? We’ll get to that later, but first some facts. Neon, of course, is not actually a molecule, but an unbonded atom that is one of the noble gases (group 18 in the periodic table). It is one of the more common elements in the universe (only hydrogen, helium, oxygen, and carbon are more abundant), but its concentration in air is only ≈18 ppm by volume.

In 1898, British chemists W. Ramsay and M. W. Travers discovered neon by condensing air and capturing its components as they evaporated. During the same series of experiments, they also identified noble gases krypton and xenon (helium and argon had been discovered earlier). Considering the scarcity of these gases and the equipment available to chemists at the time, this was a remarkable achievement.

So where does Christmas come in? Ramsay and Travers almost immediately found that neon produces a brilliant red-orange light when it is subjected to electric discharge in a vacuum. In 1912, G. Claude at Air Liquide (Paris) began to produce and sell neon discharge tubes for use in advertising signs. As time went on, people began to use them in Christmas decorations. But don’t let your friends tell you that they saw a beautiful display of blue or green neon lights. Neon’s glow is only red; the other colors are produced from different noble gases.

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