Noble gases, which have a completely filled valence shell, show little chemical activity. At ordinary temperature they do not show chemical reactivity. However, a large number of compounds of these gases particularly those of xenon and krypton have been prepared. Read the above passage and answer the following questions.

(i) Write one use of each Ar and Kr.


(ii) What are the values associated with the use of helium in artificial respiration in deep sea diving?

(i) The use of argon is as follows:

Argon is inert in its nature and hence it is used in filament bulbs to provide the inert medium and to avoid the burning of the metal.


The use of Krypton is as follows:


Krypton is also used in fluorescent bulbs, flashbulbs and lasers. Lamps filled with krypton are used as approach lights at airports as the light from these lamps can travel far even in dense fog.


(ii) Helium is generally added to protect the divers from the toxic effects of nitrogen and the percentage of helium is 11.7%.


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