Question

Which of the following p-block element does not show allotropy?

• A. C
• B. Si
• C. N
• D. P

Answer 1

The correct option is C N

The solid elements of Group 15 exist as a number of allotropes. Except nitrogen, all the elements show allotropy. Group 14 elements except lead exist as several allotropes.

Phosphorus exists in numerous allotropic structures. Of these, the two critical allotropic structures are red phosphorus and white phosphorus.

Due to the property of catenation and $p\pi$-$p\pi$ bond formation, carbon is able to show allotropic forms.
Allotropic forms of carbon can be crystalline and amorphous.
Diamond and graphite are two well-known crystalline forms of carbon. Third form of carbon known as fullerenes.