Which term describes the extent to which a material will return to its original shape after deformation?

• A. Plasticity
• B. Elasticity
• C. Toughness
• D. Ductility

Answer: (B)

Elasticity describes how well a material returns to its original shape after the deforming forces are removed. When a material is deformed within its elastic range, its atoms shift but the bonds are not permanently stretched, so it snaps back to its initial geometry once the load is released. The amount of return is tied to how stiff the material is, quantified by the modulus of elasticity (Young’s modulus) in the elastic region. If the stress exceeds the elastic limit, some deformation becomes permanent, and the material won’t fully recover its shape. The other terms refer to different behaviors: plasticity is permanent deformation, toughness is the energy a material can absorb before fracturing, and ductility is the ability to undergo significant plastic deformation before fracture.