Final answer:
Metallic solids are the type of crystalline solids where metal atoms are arranged in regular geometric patterns, forming distinct structures such as the unit cell. The correct answer is option: d. metallic solids
Step-by-step explanation:
The type of crystalline solids that have metal atoms arranged in regular geometric patterns are known as metallic solids. These solids feature metal atoms packed closely together in repeating patterns, such as hexagonal closest-packed structures, cubic closest-packed structures, body-centered structures, and simple cubic structures.
Each of these arrangements describes the unit cell of the crystalline solid, which repeats in three dimensions to form the overall structure. These geometric patterns in metallic solids contribute to their distinct properties such as malleability and ductility.