What best describes the properties of PET?

The properties of PET (polyethylene terephthalate) that best align with the correct answer emphasize its lightweight and clear characteristics. PET is commonly known for being a highly durable yet lightweight plastic, which makes it ideal for various applications, including packaging materials like bottles and containers.

Additionally, PET has excellent clarity, which allows for easy visibility of contents within containers, enhancing its utility in the food and beverage industry. This transparency, along with its strength and resistance to impact, contributes significantly to its popularity as a material. These properties make PET a preferred choice for many products where visibility and weight considerations are important.

In contrast, other properties associated with the incorrect choices do not accurately reflect PET. For example, while PET is indeed strong, it is not heavy (therefore eliminating the first choice), and it is designed to resist brittleness—making it not typically classified as hard or brittle. Instead, it maintains a substantial degree of flexibility, but not to the extent of being classified as notably stretchable, which is better associated with materials like elastomers. This understanding contextualizes why the characteristics of being lightweight and clear accurately describe PET.