Which of the following has the strongest interparticle forces at the room temperature?
The stronger the interparticle forces (between particles), the shorter the distance between those particles and the denser it is. In solids, stronger interparticle forces exist between the particles. In given options, chalk and steel are the only solids. Chalk and steel both are solids so they have strong intermolecular force but chalk can be broken easily, therefore, steel is having stronger intermolecular force when compared to chalk. So, we can conclude that among the given four, steel has the strongest intermolecular force.