How does a Neon Sign Work?

Contributed by: Maggie M.

Date of Publication: September 30, 2011

A neon sign is simply sealed luminous light tubes with metal electrodes at both ends of each tube. Inside the tubes are millions of atoms hurtling around and when a strong electric voltage is applied to the electrodes the atoms are ionized. Some of the atoms are let loose and the electrons can be turned into ions. The ions, electrons and atoms are scrambling around with kinetic energy. If one of them has a collision they can absorb the energy. This can cause the atom, electron, or ion to be unstable so it quickly tries to get rid of the extra energy. It does this by removing particles of light called photons. Neon is an example of one of the types of atoms that glow. Others are argon, mercury, helium, and xenon. Mixing these gases can make a very diverse variety of colors.
Figure 1: Neon OPEN sign- Before and After


There are many different colors that can be made with just the least amount of noble gases. Some of the gases you wouldn’t think would be a good gas to put in side of a neon sign, but they are. Some of the gases are argon, helium, neon, krypton, and xenon. Neon by its self is red but if you mix neon with argon you can get a green. Other examples are argon and mercury is yellow, argon and xenon is a pinkish violet, and helium makes gold. These gases are 1% of the air we intake every day.
Figure 2: Elements of a Neon Sign


Neon was discovered in 1898 by two British chemists named William Ramsay and Morris W. Travers. Neon has no taste color or smell and does not burn. Neon is normally used in electric signs and florescent light bulbs. Neon is in the air that we breathe daily. To use this chemical, scientists know exactly what to do to extract it from the air.
Figure 3: Neon Chemical Symbol


Ion: an electrically charged atom or group of atoms that has the loss or the gain of an electron
Ionize: to separate or change into ions
Argon: Colorless, odorless chemically inactive element that can sometimes be used for filling florescent and incandescent lamps
Xenon: A heavy colorless, chemically inactive element that can be used to fill radio, television, and luminescent tubes
Mercury: The only element that is liquid and at room temperature
Kinetic Energy: The energy in a body or system with respect to the body or the particles of the system
Photon: An amount of electromagnetic radiation, usually used as an elementary particle


Wikipedia. "Neon Sign." Wikipedia. Wikipedia. 15 September 2011. Web. 13 September 2011
Britannica Elementary Encyclopedia. "Neon." Encyclopedia Britannica Online School Edition. Encyclopedia Britannica, Inc., 2011. Web. 12 September 2011.
Woodford, Chris et al. Cool Stuff and how it Works. New York: DK Publishing Inc., 2005. Print. “Ion, Ionize, Argon, Xenon, Mercury, Kinetic Energy”, 2011. Web. 20 September 2011.