Final answer:
Fe, or elemental iron, is the solid that will most easily conduct electricity because it is a metallic solid with a sea of delocalized electrons, unlike the ionic nature of FeO₂, MgF₂, and FeCl₃ which generally do not conduct electricity when solid.
Step-by-step explanation:
On the basis of chemical structure, the solid among FeO₂, MgF₂, Fe, and FeCl₃ that will most easily conduct electricity is Fe, which is elemental iron. This is because Fe is a metallic solid, characterized by a sea of delocalized electrons that are free to move, allowing it to conduct electricity. In contrast, FeO₂ and MgF₂ are ionic solids, which typically do not conduct electricity in solid form but may conduct when molten or dissolved in water due to the mobility of their ions. FeCl₃ is also ionic in nature and follows similar principles regarding conductivity. The ability of metallic solids to conduct electricity well is due to the electron sea model, where electrons can migrate through the lattice, facilitating electrical flow.