The Noble Cases Neon, Krypton and Xenon

Applications of the Noble Cases Neon, Krypton and Xenon... 

By 1898, Ramsay and his assistant Morris Travers (1872-1961) had discovered neon, krypton, and xenon. All of them were chemically inert, so they were called the noble gases (they would not mix with common elements), and also they could be found in trace amounts in atmospheric air. In terms of the periodic table, this meant that a new column was needed, but, rather than disrupt the whole system, it actually confirmed the utility of the periodic system. Ramsay had predicted the characteristics of the new elements, and their characteristics had come out close to the expected values in each case. The last element of the column was added in 1903 with the discovery of the radioactive element radon by Frederick Soddy. In 1904, Ramsay won the Nobel Prize for chemistry for his work. 

The acentric factor increases with the size of the molecule, but only in extreme cases values >1 can be obtained, for example, for hydrocarbons with a molar mass >300. Helium (o) = —0.39) and hydrogen (co = —0.216) have negative acentric factors as so-called quantum gases. Methane and the noble gases argon, krypton, xenon, and neon have acentric factors close to 0. Otherwise, co < 0 can be ruled out. If such a value is evaluated, something is wrong with the vapor pressure curve or the critical point. 

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