Which property describes a material's ability to return to its original shape after removing a deforming force?

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

Answer: (A)

Elasticity is the property that describes a material’s ability to deform under a load and then return to its original shape once the load is removed. This behavior occurs when the deformation stays within the elastic limit, so the internal structure springs back to its initial arrangement.

Think of a rubber band or a metal spring: they stretch, but when you release them, they snap back to their original size. If the material is deformed beyond its elastic limit, it won’t fully recover, and permanent changes occur—that’s plastic deformation.

Other options don’t fit this idea: plasticity refers to permanent, non-reversible shaping; ductility is about how much plastic deformation a material can undergo before fracturing; viscosity describes a fluid’s resistance to flow, which isn’t the same as a solid’s ability to snap back after a deforming force is removed.

So, the correct concept is elasticity.