Thu December 22, 2011 By:

Read the following paragraph in a book on Inorganic Chemistry: " All Elements except Bismuth show allotrpy. Nitrogen exists in two solid allotropic forms ?-nitrogen and ?-nitrogen with hexagonal crystalline structure. The transition temperature is -283.5° " while NCERT has something else to say. It says: "Except Nitrogen all elements show allotropy. " Can it be justified. Which among the two is true ??!?

Expert Reply
Fri December 23, 2011

At low temperature nitrogen only exists as N2 molecule. So, it is said that nitrogen donot show allotropy.

But unstable allotropes of nitrogen consisting of more than two nitrogen atoms have been produced in the laboratory, like N3 and N4. Under extremely high pressures and high temperatures (2000 K), nitrogen polymerizes into the single-bonded cubic gauche crystal structure.

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