Elastomers — elongation and flexibility of natural rubber Among common elastomers, natural rubber shows the widest practical elongation range. Its typical ultimate elongation is of the order of what percentage range?

Introduction / Context:
Elastomers are characterized by large elastic (and viscoelastic) deformations before rupture. Natural rubber (NR) is notable for its high extensibility and resilience, which is central to applications like tires, vibration isolators, and flexible mounts. The question asks for the practical order of elongation in percent.

Given Data / Assumptions:

• Natural rubber compounds typically show ultimate elongation in the hundreds of percent.
• Compounding (fillers, plasticizers, crosslink density) affects the exact value.
• We are choosing an order-of-magnitude range rather than a single exact number.

Concept / Approach:
Unfilled or lightly filled natural rubber can demonstrate ultimate elongation approaching roughly 700–900% under standard tensile tests. Filled and highly crosslinked compounds reduce elongation. Therefore, a broad “up to about 1000%” range fits widely cited practice and textbook data.

Step-by-Step Solution:
Recall typical NR properties: tensile strength with ultimate elongation often 700–800%.Choose the option that reasonably brackets this range.Select 1–1000% as the appropriate order-of-magnitude span.

Verification / Alternative check:
Materials handbooks list NR ultimate elongation commonly ~500–800% depending on formulation; a top-end figure near ~1000% is often cited for soft, lightly crosslinked compositions.

Why Other Options Are Wrong:

• 1000–1500%, 1500–2000%, 2000–2500%: exceed practical values for NR; such extensions are atypical and beyond common reported data.

Common Pitfalls:

• Confusing elongation at break with elastic (recoverable) stretch.
• Ignoring the effect of fillers and crosslink density on elongation.

Final Answer:
1–1000