What property of a material allows it to absorb energy in the elastic range?

The property that allows a material to absorb energy in the elastic range is resilience. Resilience defines the capacity of a material to store elastic energy when it is deformed and to release that energy upon unloading, meaning it can return to its original shape and size without permanent deformation. This characteristic is particularly important in applications where materials experience cyclic loading, as they can withstand stresses and strains without suffering material failure.

In contrast, toughness is related to a material's ability to absorb energy before fracturing, which includes both elastic and plastic ranges. Elasticity refers to the ability of a material to deform under stress and return to its original shape, but it does not specifically focus on energy absorption. Relaxation relates to the gradual decrease in stress under constant strain, which does not pertain to energy absorption in the elastic range specifically. Thus, resilience is the most accurate term for the energy absorption property in the elastic range.