Melting point of crystalline solids Why crystalline solids have sharp melting points but melting point of amorphous solids vary within a range?


Is it because the interaction energy is equal between atoms of crystalline solids so they require equal energy to break the bond or is it because the atoms of crystalline solid are similar and are equally distant so energy gets transferred to every molecule equally so all the bonds break simultaneously.
Remember that temperature is a macroscopic quantity, telling the heat content of system. So if the crystalline solid is at its fusion temperature, and every atom in the crystals have equal interaction energy with each other (ignoring all defects of lattice), the whole solid should fuse simultaneously, thus having sharp melting point.
On the other hand, amorphous solids don't have uniform lattice and interaction energies of atoms/molecules may differ. So even at the same temperature, the whole solid might not melt, so we say amorphous compounds melt at range of temperatures.