What describes a crystalline polymer?

A crystalline polymer is characterized by a well-defined, geometric arrangement of its molecular chains. This ordered structure leads to regions of high density and strong intermolecular forces, which contribute to the rigidity and strength of the polymer. The geometric arrangement enhances the effectiveness of these strong bonds, allowing for better mechanical properties, such as high tensile strength and resistance to deformation.

In contrast, polymers with a random chain arrangement, as mentioned in another choice, typically exhibit lower tensile strength because the disordered structure leads to weaker intermolecular forces and less effective load distribution. Additionally, the concept of being mainly amorphous with a low melting point applies to materials that lack the ordered structure seen in crystalline polymers, indicating a different type of behavior and performance under heat and stress. Finally, while some polymers may be flexible or rubber-like, this characteristic does not align with the defining attributes of a crystalline polymer, which are more aligned with rigidity and strength.