The correct option is **C. Synthetic polymers can be engineered to have specific properties, such as elasticity or tensile strength.** ### Detailed Explanation: 1. **Understanding Synthetic Polymers:** - Synthetic polymers are man-made materials created through the polymerization of monomers. Common examples include plastics like polyethylene, polystyrene, and nylon. - One of the key advantages of synthetic polymers is that they can be designed and engineered to exhibit specific physical and chemical properties. This means that scientists and engineers can tailor these materials for particular applications, such as making them more flexible, stronger, or resistant to heat and chemicals. 2. **Engineering Specific Properties:** - For instance, if a manufacturer needs a polymer that is highly elastic (like rubber), they can adjust the polymerization process or the types of monomers used to achieve that desired elasticity. - Similarly, if high tensile strength is required (as in the case of materials used in construction or automotive applications), the polymer can be engineered to enhance its strength through cross-linking or by incorporating reinforcing agents. 3. **Comparison with Natural Biopolymers:** - Natural biopolymers, such as proteins, cellulose, and starch, are produced by living organisms and have evolved over millions of years. While they also have specific properties, they are generally less customizable than synthetic polymers. - For example, while silk (a natural polymer) has excellent tensile strength, it cannot be easily modified to enhance its properties in the same way synthetic polymers can. ### Why the Other Options Are Incorrect: - **A. Synthetic polymers are always biodegradable.** - This statement is incorrect because most synthetic polymers are not biodegradable. Materials like polyethylene and polystyrene can persist in the environment for hundreds of years. While there are biodegradable synthetic polymers (like polylactic acid), it is not accurate to say that all synthetic polymers share this characteristic. - **B. Natural biopolymers are typically more uniform in structure than synthetic polymers.** - This statement is misleading. While natural biopolymers can have a uniform structure due to their biological origins, synthetic polymers can also be manufactured to have a high degree of uniformity. In fact, many synthetic polymers are designed to have consistent molecular weights and structures, which can be more uniform than some natural biopolymers that may have variations due to biological processes. - **D. Natural biopolymers do not have any commercial applications.** - This statement is false. Natural biopolymers have numerous commercial applications. For example, cellulose is used in paper and textiles, proteins are used in food and pharmaceuticals, and chitosan (derived from chitin) is used in wound dressings and water purification. Thus, it is incorrect to claim that they lack commercial applications. ### Summary of Key Points: - **Synthetic polymers can be engineered** for specific properties, making them versatile for various applications. - **Natural biopolymers** are less customizable but have important roles in nature and industry. - **Not all synthetic polymers are biodegradable**, and many persist in the environment. - **Natural biopolymers have significant commercial applications**, contrary to the claim in option D. This understanding of synthetic versus natural polymers is crucial for anyone studying chemistry, especially in fields related to materials science and environmental chemistry.