There are two types of solids including amorphous solids and crystalline solids. In crystalline solids, the particles are arranged in an orderly repeating pattern. This pattern extends in all three spatial dimensions. These particles may consist of ions, atoms and molecule. The process of formation of crystals is known as crystallization and its scientific study is known as crystallography. The ionic crystals are formed when negative and positive ions are combined. The attractive forces present between ionic crystals are electrostatic forces. The ionic crystals have high melting points. London and dipole dipole forces are present in polar molecules. They are poor conductor of heat and electricity. Moreover, non-polar crystals have London forces between them and they have low melting points.

More differences between crystalline substances and amorphous substances