Final answer:
Beach balls are made from highly branched LDPE, which allows them to be flexible and inflatable, while hard plastic bottles are made from HDPE, featuring relatively few branches leading to a denser and more rigid material.
Step-by-step explanation:
Beach balls and hard plastic bottles are both products made from polyethylene, a versatile material used widely in the manufacturing of various products. The properties of polyethylene can vary greatly depending on its structure, which influences how it is used. In the case of beach balls and hard plastic bottles, the difference lies in the branching of the polymer structure. Beach balls are made from a more highly branched form of polyethylene called LDPE (Low-Density Polyethylene), which gives them flexibility and the ability to be inflated. On the other hand, hard plastic bottles require strength and rigidity, hence they are made from HDPE (High-Density Polyethylene) which has relatively few branches.
The categorization into LDPE and HDPE is crucial because it determines the density and rigidity of the final product, making certain types of polyethylene better suited for different applications. HDPE's lower degree of branching allows for tighter packing of polymer chains, resulting in stronger and more rigid materials. Conversely, LDPE's higher degree of branching prevents the chains from packing closely together, leading to a material that is less dense and more flexible, which is ideal for products like beach balls.