Final answer:
The external form and symmetry of a crystal reflects its atomic arrangement, as atoms form lattices that maximize attractive interactions and minimize energy.
Step-by-step explanation:
The external form and symmetry of a crystal reflects its atomic arrangement. This is because atoms arrange themselves into a lattice structure due to the net attractive force between their electrons and atomic nuclei. These arrangements are visually and structurally evident in the crystalline forms of solids, with ionic, covalent, and metallic being the primary types of bonding that contribute to crystal formation. The regular atomic arrangement maximizes the attractive interactions and minimizes total intermolecular energy, resulting in the diverse and characteristic external forms of crystals we observe.