Which of the following is an elastomer?

Options

A. Bakelite
B. Polythene
C. Buna-S
D. Polystyren

Answer

To determine which of the given options is an elastomer, we can follow these steps:

### Step 1: Understand the Definition of Elastomers
Elastomers are polymers that exhibit elastic properties, meaning they can stretch and return to their original shape. They are typically held together by weak intermolecular forces.

### Step 2: Analyze the Given Options
The options provided are:
1. Bakelite
2. Polythene
3. Buna-S
4. Polystyrene

### Step 3: Classify Each Option
- **Bakelite**: This is a thermosetting plastic, which means it cannot be reshaped once set. It does not have elastic properties.
- **Polythene**: This is a thermoplastic, which is flexible but not classified as an elastomer.
- **Buna-S**: This is a synthetic rubber made from the polymerization of 1,3-butadiene and styrene. It has elastic properties and is classified as an elastomer.
- **Polystyrene**: This is another thermoplastic that does not exhibit elastic properties.

### Step 4: Identify the Correct Answer
From the analysis, the only option that qualifies as an elastomer is **Buna-S**.

### Conclusion
The correct answer is **Buna-S**.

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