The correct option is **A. Polyethylene terephthalate (PET)**. ### Detailed Explanation: 1. **Understanding Synthetic Polymers**: Synthetic polymers are large molecules made up of repeating structural units (monomers) that are chemically bonded together. They are widely used in various applications, including packaging, textiles, and construction, due to their versatile properties. 2. **Properties of PET**: - **Durability**: PET is known for its strength and durability. It can withstand physical stress and is resistant to impact, making it ideal for products that need to maintain their shape and integrity. - **Chemical Resistance**: PET is resistant to many chemicals, including acids and bases, which makes it suitable for storing a variety of substances without degrading or reacting with the contents. - **Transparency**: PET is clear and can be made to have a glass-like appearance, which is aesthetically pleasing for consumer products like bottles. - **Recyclability**: PET is one of the most recycled plastics, which adds to its appeal in sustainable practices. 3. **Applications of PET**: Due to its properties, PET is commonly used in the production of plastic bottles (like those for soft drinks and water) and containers for food and other products. Its ability to maintain the quality of the contents while being lightweight and shatter-resistant makes it a preferred choice in the packaging industry. ### Why the Other Options Are Weaker: - **B. Polystyrene (PS)**: - **Properties**: Polystyrene is a versatile plastic but is generally more brittle than PET. It is not as durable and can break easily under stress. - **Chemical Resistance**: While it has some resistance to certain chemicals, it is not as robust as PET in this regard. - **Applications**: Polystyrene is often used for disposable cutlery, foam packaging, and insulation materials, but it is not commonly used for bottles due to its fragility. - **C. Polyvinyl Chloride (PVC)**: - **Properties**: PVC is known for its rigidity and is often used in construction materials (like pipes) and some packaging. However, it can be less durable than PET when it comes to impact resistance. - **Chemical Resistance**: PVC has good chemical resistance but can release harmful chemicals when burned or improperly disposed of. - **Applications**: While PVC is used in some containers, it is not the primary choice for bottles due to its rigidity and potential health concerns. - **D. Polypropylene (PP)**: - **Properties**: Polypropylene is flexible and has a higher melting point than PET, making it suitable for applications that require heat resistance. However, it is generally less transparent than PET. - **Chemical Resistance**: It has good chemical resistance but is not as widely used for beverage containers as PET. - **Applications**: Polypropylene is often used in food containers, automotive parts, and textiles, but it does not have the same level of consumer acceptance for beverage bottles as PET. ### Summary of Key Points: - **PET** is the most suitable polymer for plastic bottles due to its durability, chemical resistance, and recyclability. - **Polystyrene** is brittle and not ideal for bottles. - **PVC** is rigid and has health concerns associated with it. - **Polypropylene** is flexible but lacks the transparency and consumer acceptance of PET for beverage containers. In conclusion, when considering the properties and applications of synthetic polymers, PET stands out as the best option for producing durable and chemically resistant plastic bottles and containers.