Pblock Elementsii Result Question 30
Passage
The noble gases have closed-shell electronic configuration and are monoatomic gases under normal conditions. The low boiling points of the lighter noble gases are due to weak dispersion forces between the atoms and the absence of other interatomic interactions.
The direct reaction of xenon with fluorine leads to a series of compounds with oxidation numbers $+2,+4$ and $+6 . \mathrm{XeF}_4$ reacts violently with water to give $\mathrm{XeO}_3$. The compounds of xenon exhibit rich stereochemistry and their geometries can be deduced considering the total number of electron pairs in the valence shell.
(2007, $3 \times 4 \mathrm{M}=12 \mathrm{M}$ )
30. Argon is used in arc welding because of its
(a) low reactivity with metal
(b) ability to lower the melting point of metal
(c) flammability
(d) high calorific value
Show Answer
Answer:
Correct Answer: 30. ( a )
Solution:
$Ar$, being inert, provide inert atmosphere in arc welding, and prevent from undesired oxidation.
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