noble gases

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Slide 1: 

NOBLE GASES

Slide 2: 

All are odorless, colorless, nonflamable monatomic gases (one atom) Group 18 Outer shell of valence electrons is full – low reactivity Ne < He < Ar < Kr < Xe < Rn

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Low boiling and meliting point Ccryogenic refrigerants Breathing gases Superconducting magnets

Helium : 

Helium He, atomic number 2 The second lightest and second most abundant gas in the known universe (hydrogen being number one) The discovery of helium is generally credited to Janssen and Lockyear in 1868 Helium is the only known element which cannot be converted to a solid simply by cooling Flying baloons (instead of hydrogen)

Neon : 

Neon Ne, atomic number 10 The fourth most abundant element in the known universe, neon was discovered in 1898 by Ramsay and Travers. Its name is taken from the Greek neos or "new" Neon lights No compounds The gas is extracted from air by liquefaction.

Argon : 

Argon Ar, atomic number 18 1 % volume of the atmosphere (3. most aboundant) For years argon has been used in ordinary incandescent light bulbs to replace the oxygen that would otherwise shorten the lifetime of the filament A few, but unstable compounds obtained from air using the methods of liquefaction of gases and fractional distillation

Krypton : 

Krypton Kr, atomic number 36 obtained from air using the methods of liquefaction of gases and fractional distillation In fluorescent lamps In lasers (krypton fluoride laser) High speed photography, photo flashes

Xenon : 

Xenon Xe, atomic number 54 is the rarest of the stable noble gases in the air obtained from air using the methods of liquefaction of gases and fractional distillation Sometimes combines with chlore, fluore or oxygen Used to research the geological devoloptment and history (the isotopes and their rate – stable vs. Unstable) disinfection

Radon : 

Radon Rn, atomic number 86 It also has medical applications for cancer treatment Radon is found in underground deposits where is it produced by uranium and radium decay Radon fluoride (RnF) has been produced and the element glows with a yellow light in the solid state

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