**Correct Option: C. Polyethylene terephthalate (PET)** ### Detailed Explanation: **1. Understanding the Properties of PET:** Polyethylene terephthalate (PET) is a type of polyester that is widely used in the production of plastic bottles, especially for beverages. It is favored for several reasons: - **Lightweight:** PET is significantly lighter than glass, making it easier to transport and handle. - **Recyclability:** PET is one of the most recycled plastics globally. It can be reprocessed into new products, which helps reduce waste and conserve resources. - **Durability:** PET is resistant to impact and can withstand a range of temperatures, making it suitable for various applications, including hot-fill products. **2. Why PET is the Correct Answer:** - **Common Use in Bottles:** PET is the standard material for soft drink and water bottles. Its properties allow it to maintain the integrity of the beverage while being lightweight and easy to mold into various shapes. - **Recyclability:** PET is marked with the recycling code "1," indicating that it is widely accepted in recycling programs. This encourages consumers to recycle, contributing to a circular economy. **3. Analysis of Other Options:** - **A. Polyvinyl chloride (PVC):** - **Usage:** PVC is commonly used in construction materials, plumbing, and electrical cable insulation. While it can be used for some types of bottles, it is not the standard for beverage containers. - **Recyclability Issues:** PVC is more challenging to recycle compared to PET and can release harmful chemicals when burned, making it less favorable for consumer products. - **B. Polystyrene (PS):** - **Usage:** Polystyrene is often used for disposable cutlery, plates, and foam packaging. It is not typically used for bottles due to its brittleness and lack of barrier properties. - **Recyclability Issues:** While it can be recycled, the process is not as widespread or efficient as PET recycling, and many recycling facilities do not accept it. - **D. Polypropylene (PP):** - **Usage:** Polypropylene is used in a variety of applications, including food containers, automotive parts, and textiles. It is more commonly used for rigid containers rather than bottles. - **Recyclability:** Although polypropylene is recyclable (marked with the code "5"), it is not as commonly recycled as PET, and its recycling infrastructure is less developed. ### Summary of Key Points: - **PET is the most common polymer for plastic bottles due to its lightweight and durable properties.** - **It is highly recyclable, making it an environmentally friendly choice compared to other plastics.** - **Other options like PVC, PS, and PP are used in different applications but are not suitable for beverage bottles.** - **Understanding the properties and applications of different polymers is crucial for recognizing their uses in everyday products.** ### Revision Summary: - **PET is the standard material for plastic bottles due to its lightweight and durable nature.** - **It is highly recyclable, contributing to environmental sustainability.** - **Other polymers like PVC, PS, and PP have different applications and limitations.** - **Recognizing the properties of materials helps in understanding their suitability for specific uses.**