Final answer:
Crystalline order describes the careful ordering of molecules within solids that have a fixed shape. The particles in crystalline solids are arranged in a regular repeating pattern called a crystal lattice, which gives them their distinct properties.
Step-by-step explanation:
The careful ordering of molecules within solids that have a fixed shape is known as crystalline order. In crystalline solids, the particles are arranged in a regular and repeating pattern called a crystal lattice. This organized arrangement gives crystalline solids their distinct properties and allows them to have a fixed shape.