By: Luke J, 2012

What is Neon?

When someone says the word “neon” you think of the big “OPEN” signs for shops and stores or just flashy, bright colors, but what is neon, exactly? Neon is number 10 in the periodic table, and has the atomic symbol “Ne”. It is named from the Greek word “neos” meaning “new”. It is classified as a noble gas, it is found in the second row, period two. Neon is a colorless, odorless gas. Neon signs don’t necessarily use neon gas. Neon signs are made up of glass tubes filled with any of the noble gases: helium, neon, argon, krypton, xenon, and radon. Each of the noble gases has a specific color, and when combined, they make more colors.

Neon Tube Diagram LJ.jpg
Figure 1- Neon Tube Diagram

A neon sign is made up of sealed tubes filled with neon gas at a low pressure. Sometimes, one or two drops of mercury are placed inside the tube to brighten the color. As seen in the diagram (left), a neon tube has electrodes on either side. It contains three types of particles, neon ions, (red particles) neon atoms, (green particles) and electrons, (blue particles). When an electric voltage is applied to the electrodes, it ionizes the gas. Some neon atoms lose electrons and become ions. The neon atoms, ions and electrons whiz around the tube in different directions. Neon ions move in the same direction as electricity, electrons move the opposite way of the electricity, and neon atoms move around randomly. The collision of the neon ion and an electron produces a red light. When neon atoms collide with neon ions, they also generate energy and emit a red light. All of the moving particles in the tube have kinetic energy. If a neon atom or ion is involved in a collision, it might absorb some of the kinetic energy. That makes it unstable, and it quickly tries to get rid of all the energy by releasing light particles called photons. Since the gas is neon, it generates a red light. With other gases, they produce different colors, such as argon emits a blue light.

The History of Neon
Georges Claude.jpg
Figure 2- Georges Claude

Neon was first discovered in 1898 by Scottish chemist William Ramsay and English scientist Morris Travelers. It was discovered when Ramsay cooled a sample of the atmosphere until it became liquid. He then boiled the liquid and captured the gases as the liquid boiled. He caught neon, xenon, and krypton, which are three of the noble gases. In 1960 French chemist, engineer and inventor Georges Claude was the first to put the neon gas into a sealed tube. Claude found out that mixing other noble gases with neon produced different colors. The very first neon light was simply a glass tube filled with neon gas that glows red when electricity passed through it. He experimented with various glass shapes and bending the glass tubes to make pictures and letters. Modern neon lamps are plastic, rather than glass, and the range of colors is much larger than what Claude discovered, for we discovered baking a fluorescent powder or painting the tube can create a whole other spectrum of colors. The neon sign is the most famous application for neon, but neon is used for other things. Neon glow lamps are also another product of neon. The first practical color TV even used a neon tube for the red color in the receiver. People created neon signs by heating the glass tube at the correct temperature, then bending the glass to the desired shaped, often words or pictures to advertise a business, product or shop.

The Noble Gases

The six noble gases are what makes a neon sign many different colors. All of the noble gases are odorless, colorless, stable, and with a few exceptions, inert.
Helium is number 2 in the periodic table, and has the atomic symbol “He”. It is classified as a noble gas; it lies in the first row, period one. Helium is colorless, odorless, tasteless and nonflammable. Helium is derived from the Greek word “helios” meaning “sun”. Helium is most widely used to blow up party balloons, and used in supersonic wind tunnels. Websites have shown varied results about the color of helium when conducting electricity, including a pinkish-red glow, a pale yellow glow, or just no color at all.
Argon is number 18 in the periodic table, and has the atomic symbol “Ar”. It is classified as a noble gas; it lies in the third row, period three. Argon gets its from the Greek word “argos” meaning “idle, or inactive”. Just like the other noble gases, argon is completely nonreactive to other elements. It is used to create an nonreactive atmosphere in different situations. It is also used to make iridescent light bulbs, to prevent oxygen from corroding the hot filaments. When put inside a neon tube and struck with high voltage, argon produces a blue light.
Krypton is another noble gas and is number 36 in the periodic table. Krypton’s atomic symbol is “Kr” and lies in the fourth row, period four. The name krypton comes from the Greek word “kryptos” meaning “hidden”. It is commonly used for lighting for high-speed photography. When conducting electricity, krypton emits a silvery white light.
Xenon, also a noble gas, is number 54 in the periodic table. Its atomic symbol is “Xe”, and it lies in the fifth row, period five. It is named after the Greek word “xenos” meaning “strange.” One of the common uses for xenon is in strobe lights and powerful lamps. It is also used for killing bacteria and to power some types of lasers. When used for conducting electricity, xenon creates a blue-violet light. Radon is number 86 in the periodic table, and has the atomic symbol “Rn”. It lies in the sixth row, period six. It is named after the word “radium”. When trapped indoors, radon can become concentrated and become a hazardous because radon is radioactive. Even though radon can be a health hazard, hospitals sometimes use radon in small doses to treat some forms of cancer. So now you know what neon and the other noble gases are, what they do, and how they benefit us in our life. It's allot more than just flashy colors or those "OPEN" signs, isn't it?

Noble Gas
Color when conducting electricity
Other Uses
Varied results
Blowing up party balloons; used in supersonic wind tunnels, etc.
Bright red
To create glow lamps, to make helium-neon lasers, etc.
Used to make iridescent light bulbs
For high-speed photography
To kill bacteria and power certain types of lasers
Varied results
To cure some types of cancer

How To Make A Neon Sign

Argon- A gaseous element that does not have a color, odor, and is inert.
Atmosphere- The gaseous envelope that surrounds the earth.
Atom- A particle of matter so small it cannot be seen.
Chemist- A specialist in chemistry.
Electrode- A conductor, not necessarily metal, through which a current enters or leaves a nonmetallic medium.
Electron- A unit of charge equal to the charge of one electron.
Helium- A gaseous element present in the sun’s atmosphere and in natural gas.
Ion- An electrically charged atom or group of atoms formed by the loss or gain of one or more electrons.
Iridescent- Displaying brilliant colors like those of the rainbow.
Inert-Having none or hardly any ability to react.
Kinetic Energy- Energy that a body possesses by virtue of being in motion.
Krypton- A gaseous element found in minute amounts in the atmosphere.
Liquid- A substance who’s molecules move freely.
Neon- A chemically inert gaseous element found in small amounts in the earth’s atmosphere.
Noble Gas- Any of the inert gaseous elements of group 8A or 0 of the periodic table.
Nonflammable- Not combustible or easy to set on fire.
Periodic Table- a table illustrating the periodic system, in which the chemical elements are in the order of their atomic weights and their atomic numbers.
Photons- A tiny particle of light, unseen to the human eye.
Radon- A chemically inert, radioactive gaseous element.
Xenon- A heavy, colorless, inactive gaseous element.

Books: “Cool Stuff and How it Works” by Chris Woodford, Lodon; New York: DK, 2005. Print.
Image: “Georges Claude” http:/ Image. September 27, 2012.
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Books: “Science of Everyday Things” by Judson Knight, Detroit, MI: Gale Group, 2002. Print.
Web: Wikipedia <http:/> September 5 2012. Web. September 27, 2012.