A colorless gas, argon gives off a blue glow when an electric current is passed through it.
A colorless gas, argon is one of the main components of electric light bulbs and fluorescent lamps. It is also widely used in arc welding and cutting, as well as a protective gas for other elements. In recent years, argon gas has also been used as a low cost insulation in double pane windows.
History and Properties
Argon's blue light is often used with other inert gases in advertising signs.
Argon was discovered in 1894 and makes up less than 1 percent of the earth's atmosphere. A member of the noble gas family, argon does not react with other elements as its outer electron shell is complete. In fact, its name comes from the Greek word "argos," meaning inactive. It is this lack of reactivity that makes it useful in preventing oxidation and acting as a preservative. Normally a colorless gas at room temperature, argon emits a rich sky blue glow when an electric current passes through it exciting its electrons. It is this blue color that is often found in fluorescent advertising signs.
Lighting and Welding
Argon gas is used as a filler in incandescent light bulbs.
Since argon is non-reactive, it is also used as a filler in incandescent light bulbs to protect the tungsten filament against oxidation. Without this protection, the filament would break after very brief usage. While any of the inert gases could be used in this function, argon is relatively abundant and thus is much cheaper than some of the other noble gases.
In welding and cutting metals, argon is used to provide a shield around the molten metal. If not for this shield, the metal would react with the atmosphere and thus become contaminated. After the welding is complete, the gas shield protects the weld while it hardens. While pure argon is used for aluminum welding, other welding makes use of argon mixed with either oxygen, carbon dioxide or helium.
Electronics, Medicine and Preservation
Argon gas is often used to preserve wine once the bottle has been opened.
With the advent of semi-conductors, argon has been used to aid the growth of germanium and silicon crystals, which need a protected environment for optimum growth. It also keeps any contaminants from altering the configuration of the crystals. Argon has also been used in medical lasers, especially in the field of ophthalmology. These lasers have aided in the correction of retinal detachments and blood vessel leakage. They have also proved effective in reducing glaucoma pressure and in treating some forms of macular degeneration.
One of the newer uses of argon gas is to add it to wine bottles that have been opened. It is claimed that adding argon gas keeps the wine from reacting with the atmosphere and thus keeps it fresher longer
