Which term describes the ability of a material to be permanently deformed and not return to its original shape?

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

Answer: (C)

When a material changes shape and does not return to its original form after the load is removed, that behavior is called plasticity. It occurs when the stress pushes the material beyond its elastic limit, causing permanent rearrangement of its internal structure. Elasticity would mean the material would snap back to its original shape once the force is released, which is not happening here. Ductility describes how much a material can be stretched or elongated before it ultimately fails, which relates to how far it can deform in tension but doesn’t specifically define the permanent shape change. Malleability refers to the ability to deform a material under compression into thin sheets. In this scenario, the lasting, non-recoverable deformation points to plasticity.