Due to vulcanization, rubber becomes

Options

A. soft
B. hard
C. less elastic
D. soluble in water

Explanation

To solve the question "Due to vulcanization, rubber becomes," we need to understand the process of vulcanization and its effects on rubber properties.

### Step-by-Step Solution:

1. **Understanding Vulcanization**:
- Vulcanization is a chemical process that involves the addition of sulfur to natural rubber.
- This process creates cross-links between the polymer chains of rubber, which significantly alters its properties.

**Hint**: Remember that vulcanization involves sulfur and is aimed at improving the rubber's properties.

2. **Properties of Natural Rubber**:
- Natural rubber is known to be elastic but has limitations; it can become soft at high temperatures and brittle at low temperatures.
- These inconsistencies in behavior at different temperatures are problematic for practical applications.

**Hint**: Consider how temperature affects the physical state of rubber before vulcanization.

3. **Effects of Vulcanization**:
- When rubber undergoes vulcanization, the cross-linking of sulfur atoms strengthens the rubber.
- This process makes the rubber more rigid and less susceptible to changes in temperature, thus improving its overall durability.

**Hint**: Think about how cross-linking affects the flexibility and strength of materials.

4. **Final Properties of Vulcanized Rubber**:
- After vulcanization, rubber becomes harder and more resilient.
- The final product is less elastic compared to its original form and is often described as stiffened or hard.

**Hint**: Focus on the term "stiffened" and its implications for the material's properties.

5. **Conclusion**:
- Therefore, due to vulcanization, rubber becomes hard or stiffened.

**Final Answer**: The correct option is "hard" or "stiffened."

### Summary:
Vulcanization transforms rubber from a soft, temperature-sensitive material into a hard, durable one by creating cross-links through sulfur bonding, thus enhancing its properties.