Group+18+Noble+Gases

The Noble Gases are found in the group 18 of the periodic table and were discovered and characterized by William Ramsay in the late 19th century. The Noble Gases are all monoatomic non-metal gases at room temperature. A clearly defining characteristic of Noble Gases is their full valence electron shells, which results in very high ionization energies. They are also very stable compounds and do not combust or readily form compounds with other elements. In fact, only two gases, Krypton and Xenon form any compounds at all. Krypton forms KrF2 in combination with Fluorine and Xenon forms three compounds in combination with Fluorine and two in combination with Oxygen. These gases all have low boiling points, for example Helium has a boiling point of 4.2K. All of the Noble Gases occur naturally in the atmosphere and can be obtained through a fractional distillation of liquid air.
 * ==General Information and Characteristics==


 * ==Practical Applications==

Because of its extremely low density, Helium is used as a flotation aid for weather balloons and "airships". Helium is particularly advantageous in this respect because of its lack of flammability, therefore preventing an incident similar to the Hindenburg from occurring. Helium is also used in gas mixtures for deep sea divers to dilute the concentration of Oxygen. http://www.funservicesinc.com/catalog/images/helium%20tanks.jpg Neon is used as a lighting device because of the brightly colored light it emits when electricity is passed through it. Its main lighting application is in advertising and fluorescent lighting.
 * Helium**
 * Neon**



http://www.lightshow.cc/explorer/Images/Kaleidoscope/Neon_Wire/lightshow_neon_wire_006.jpg

Argon is used in incandescent lighting where its lack of flammability is used to keep the filament cool. If the space inside a light bulb were filled with air, the filament would react and ignite; however, Argon prevents this from happening. The same concept is also applied in welding, where Argon is used to keep brittle metal oxides from forming and diminishing the quality of the weld. Argon is also used in lasers. Argon is the most abundant Noble Gas and is therefore the cheapest to produce. http://content.answers.com/main/content/wp/en-commons/thumb/3/3e/180px-Gluehlampe_01_KMJ.jpg
 * Argon**

Krypton is used in laser beams by surgeons to remove birthmarks and correct some eye problems. http://www.jklasers.com/Multi_beams.jpg
 * Krypton**

Xenon has a wider light spectrum than any of the other Noble Gases with a hue perceived close to that of daylight. Therefore, it is used in high efficiency incandescent light bulbs for stage lighting, in operating room lighting, and in ultraviolet lasers. http://www.gc.maricopa.edu/earthsci/imagearchive/Xenon%20sm.jpg
 * Xenon**

Radon is extremely rare and has harmful radio-isotopes. Therefore, it is both very difficult to study and to use practically. However, it is used in some forms of aggressive cancer treatment.
 * Radon**

http://www.allerair.com/artwork/pic_radon.jpg

Sources: http://www.chemsoc.org/viselements/pages/data/intro_groupviii_data.html http://www.webelements.com/webelements/elements/text/Xe/comp.html __http://en.wikipedia.org/wiki/Noble_gas__ http://www.wpbschoolhouse.btinternet.co.uk/page03/Noble_Gases.htm