Question

How many allotropes does nitrogen have?

(a) Zero

(b) One

(c) Two

(d) Three

I got this question in an international level competition.

My question is taken from P-Block Elements in chapter P-Block Elements of Chemistry – Class 12

Answer 1

The correct answer is (a) Zero

The explanation is: Nitrogen atom does not exhibit allotropy. This is because of its relatively small size and high inter-electronic repulsion due to which the N – N becomes extremely weak. However, theoretically there are two predicted forms of allotropes of nitrogen. First, alpha nitrogen assumes a cubic structure and exists only below 35.6 K which is a whooping -237.55°C. Beta nitrogen exists from 35.6 K to 63.15 K. After that, it melts.