What describes a material's ability to absorb energy before breaking?

The concept that describes a material's ability to absorb energy before breaking is toughness. Toughness is a measure of how much energy a material can absorb before it fractures. It indicates the material's resistance to fracture when subjected to stress, showcasing both its strength and ductility. A tough material can undergo significant deformation and absorb considerable energy without failing, making it especially valuable in applications where impact resistance is critical.

In contrast, elasticity refers to a material's ability to return to its original shape after the removal of stress, while ductility is specifically the ability of a material to deform plastically before fracturing. Plasticity involves permanent deformation, but it does not necessarily imply the ability to absorb energy without breaking as toughness does. Thus, toughness encapsulates the overall capacity of a material to withstand energy before reaching a breaking point, making it the correct choice in this context.