Which of the following has the strongest intermolecular force of attraction between its particles at room temperature?
Iron
As we know, more the distance between the particles, lesser is the force of attraction between them. We also know that the distance between the particles in a gaseous substance is more than that of a solid.
1. Nitrogen is a gas at room temperature. So, it's particles have more space and less attraction between them than a solid.
2. Mercury is liquid at room temperature. So, it's particles have comparatively more space and less attraction between them, than a solid. However, its particles have less space and more attraction in between them as compared to gases.
3. Chalk piece is solid but can be easily broken because its particles have weak forces of attraction than that of an iron.
Therefore, among the given four options, iron has the strongest intermolecular force of attraction between its particles at room temperature