Which type of solids have uniform and repeating arrangements of particles?

Crystalline solids are characterized by a uniform and repeating arrangement of their constituent particles, which can be atoms, ions, or molecules. This orderly structure is the result of the particles being held together by various types of bonding (ionic, covalent, or metallic) in a well-defined geometric pattern. The regular arrangement contributes to distinctive properties such as sharp melting points, specific heat capacities, and various optical properties like birefringence.

The uniformity of the crystalline structure means that, when viewed at a microscopic level, the particles are organized in a regular pattern that repeats throughout the entire solid. This can be contrasted with other types of solids. For instance, amorphous solids lack such long-range order, resulting in a disordered arrangement of particles. Similarly, while polymers can exhibit ordered structures in certain contexts, they do not inherently have the repeating patterns found in crystalline solids. Aromatic solids, while related to organic compounds with resonance structures, do not represent a specific class of solid defined by repeating particle arrangements.

Therefore, crystalline solids stand out due to their clear, repeating structure, which contributes significantly to their unique physical properties.