Answer: Option C
:
C
As we know, more the distance between the particles, lesser is the force of attraction between them. Nitrogen is a gas at room temperature. So, its particles have more space and less attraction between them than a solid.
Mercury is liquid at room temperature. So, its particles have comparatively more space and less attraction between them, than a solid.
Chalk piece can be easily broken because its particles have weaker force of attraction than that of iron.
Hence, the correct order of force of attraction is as follows:
Nitrogen < Mercury < Chalk < Iron