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How Do Neon Lights Work

Abhijit Naik
Not many people out there would need an introduction to neon lights which have been in the picture for almost a century now, but how these lights work is something which not many people are actually aware of. Continue reading...
The concept of neon lighting, also known as neon tube lighting, was introduced by Georges Claude - a French engineer and inventor, back in 1910. Over the next two decades, the use of custom neon signs for advertising became quite popular all over the world, and the United States was no exception to this.
Such is the popularity of neon signs, that even those signs which don't resort to neon gas are referred to as neon signs nowadays.

Neon Facts

Neon is one of the six noble gases which come together to form Group 18 of the periodic table. A colorless, odorless and tasteless gas, neon is known to exist in abundance in the universe, but only in trace amounts on the Earth. While it was initially believed that neon is inert in nature, recent studies have revealed that the same can combine with fluorine to produce new compounds and with other noble gases to form ions.
Since its discovery by Sir William Ramsay and Morris Travers in 1898, neon has come a long way to become one of the most widely used gases of the lot, and all these uses of neon are attributed to its physical and chemical properties. The use of neon in advertising signs is mainly attributed to its ability to produce distinct reddish-orange glow.

How Do Neon Lights Work?

A neon light, as its name suggests, is made by filling a sealed glass tube with neon. At either ends of this glass tube lie two metal electrodes - one of which provides negative charge to the tube while other provides a positive charge. When the tube is subjected to high voltage, the positively charged ions move towards negative terminal and negatively charged electrons move towards the positive terminal.
In order to reach their destination, these ions and electrons rely on the atoms of neon gas present within the glass tube. When these ions and electrons collide with neon atoms they generate small packets of energy which is absorbed by the neon atoms.
In order to return to normalcy, these neon atoms need to release the energy that they have absorbed in course of collision. This energy is released by these atoms in form of photons, and these photons give neon lights their characteristic reddish glow, which makes them so appealing.

How do Neon Lights Get their Color?

In normal circumstances, the photons produced by neon atoms are red in color, while the photons produced by argon are blue in color. However, it is possible to change the red glow of neon lights to a different color by resorting to different methods.
One of the most widely used method for this is to add mercury to the glass tube. Adding varying amount of mercury to the glass tube can help in producing a variety of colors.
Yet another, but a bit expensive, method is to produce the neon gas at a specific atomic orbital so as to make sure that the gas in itself produces the desired colored glow instead of the traditional red glow. A mixture of two noble gases can also help in producing a distinct glow, and the use of neon and argon in the glass tube to produce a green glow of light is the best example of this.
There does exist yet another method which is a lot cheaper than the aforementioned methods though. In this method, the glass tube in itself is painted with a shade of the color that you want the neon light to be, which in turn makes sure that the sign illuminates in that particular color, even if the photons within are producing a different color.
However, these lights do not produce a bright glow as other neon lights do, and this inefficiency can be attributed to the shade of paint which coats the glass tube.