Answer:
It reduces the melting point due to a defect in the arrangement of the crystal lattice.
Explanation:
The presence of impurities creates a disorderliness in the uniformity of the crystal structure. It lowers the melting point by a few degrees because it becomes easier to overcome the intermolecular force of attraction.
It makes the array of crystals disordered.
Lattice is a long chain three-dimensional arrangement of the molecules, atoms or ions in a crystal structure.