Noble Gas | Noble Gas Electron Configuration | Chemistry@TutorVista.com
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[Ar] d1s2
Instead of using the full shell the noble gases can be used in conjugation with the electron configuration to form the noble gas notation. This notation makes it easier to identify elements, and is shorter than writing out the full notation of atomic orbitals.
Noble Gas Uses
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Helium is used in preference to N2 to dilute O2 in gas cylinders used by sea divers.
A mixture of He and O2 is also used to assist breathing in asthma and other respiratory diseases because this mixture is lighter than air.
Helium is also used in weather balloons and airships in the place of H2.
Neon is used in neon discharge tubes which gives familiar reddish orange yellow glow of neon signs.
Argon provides inert atmosphere for metallurgy.
Krypton and xenon are used in filling incandescent metal filament electrical bulbs as these gases are found superior to argon for this purpose.
Radon is useful in the treatment of cancer because it is radioactive in nature.
Characteristics of Noble Gases
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Electronic configuration - All noble gases except helium have highly stable general electronic configuration in the valence shell that is ns2np6. Helium has ns2 stable configuration.
Atomic radii - Atomic radii of noble gases increases on moving down the group and their atomic radii correspond to the van der Waals radii.
Boiling points - As the magnitude of van der Waals forces increases down the group, boiling points also increases in the same order.
Ease of liquefaction - The van der Waals forces in these gases are weak, as such these gases are relatively difficult to be liquefied. Further as the van der Waals forces increase from He to Xe, the ease of liquefaction increases with increase in atomic weight.
Polarisability - The polarisability of the electron clouds in valence shell increases down the group as these electron clouds get away from nucleus as one goes down in the group.
Ionization energy and electron affinity - These elements have stable ns2np6 electronic configuration therefore they have no tendency to lose or gain electrons.
Solubility - They are generally less soluble in water. However their solubility increases with increase in atomic weight down the group.
Electrical conductivity - Noble gases have fairly good electrical conductivity at low pressure and high voltage.
Chemical reactivity - Krypton, xenon and radon have been found to react chemically and the reactivity increases down the group.
Noble Gases on Periodic Table