The correct option is **B. Polystyrene**. ### Detailed Explanation: 1. **Understanding Polymers**: - Polymers are large molecules made up of repeating structural units called monomers. The process of forming a polymer from monomers is known as polymerization. 2. **Styrene as a Monomer**: - Styrene is an organic compound that serves as a key monomer in the production of polystyrene. Its chemical structure is C8H8, which consists of a vinyl group (–CH=CH2) attached to a phenyl group (–C6H5). 3. **Polymerization Process**: - The polymerization of styrene typically occurs through a process called free radical polymerization. In this process, free radicals initiate the reaction, leading to the formation of long chains of polystyrene. The reaction can be summarized as follows: \[ n \, \text{C}_8\text{H}_8 \rightarrow \text{(C}_8\text{H}_8\text{)}_n \] - Here, \( n \) represents the number of styrene monomers that join together to form the polymer. 4. **Applications of Polystyrene**: - Polystyrene is widely used in the production of foam products, such as packaging materials (like Styrofoam), insulation materials, and disposable cutlery. Its lightweight and insulating properties make it ideal for these applications. ### Why Other Options Are Incorrect: - **A. Polyethylene**: - Polyethylene is made from the polymerization of ethylene (C2H4), not styrene. It is commonly used in plastic bags, bottles, and containers. While it is a versatile polymer, it does not have the same properties or applications as polystyrene. - **C. Polyvinyl Chloride (PVC)**: - PVC is produced from the polymerization of vinyl chloride (C2H3Cl). It is primarily used in construction materials, plumbing, and electrical cable insulation. Like polyethylene, it does not relate to styrene and is used for different applications. - **D. Polypropylene**: - Polypropylene is made from the polymerization of propylene (C3H6). It is used in a variety of applications, including packaging, textiles, and automotive parts. Again, it does not involve styrene and has different properties compared to polystyrene. ### Common Pitfalls: - Students may confuse the names of different polymers and their corresponding monomers. It is essential to remember the specific monomer associated with each polymer. - Misunderstanding the applications of each polymer can lead to incorrect answers. Knowing the common uses of each polymer helps in identifying the correct one. ### Revision Summary: - **Polystyrene** is the polymer made from the polymerization of **styrene**. - It is commonly used in **foam products** and **insulation materials**. - Other options (polyethylene, PVC, polypropylene) are made from different monomers and have distinct applications. - Understanding the structure and applications of each polymer is crucial for identifying them correctly.