GENERAL KNOWLEDGE

Detailed explanation-1: -Nitrogen has the lowest boiling point because in group 15 elements the boiling point increases down the group.

Detailed explanation-2: -The interactions between nitrogen molecules (N2) are weaker, so the boiling point is lower. Interactions between nonpolar molecules depend on the degree of electron fluctuation within the molecule.

Detailed explanation-3: -So, NO has the highest boiling point. The london dispersion forces are stronger for molecules of higher molar mass. Since, O2 has higher molar mass than N2, the boiling point of O2 is higher than that of N2. Therefore, the increasing order of boiling point is as follows: N2 O2 NO.