Which of the following affects the elasticity of a substance?

Explanation

The elasticity of a substance, which is its ability to return to its original shape after deformation, can be influenced by several factors:Impurity: Impurities can introduce defects in the atomic structure of a solid, affecting its elastic behaviour.Hammering and annealing: These mechanical processes can alter the internal structure of a material, changing its mechanical properties, including elasticity.Change in temperature: Temperature influences the movement of atoms and the strength of bonds, therefore impacting elasticity.Therefore, the correct answer is Option D: All of these, as each listed factor can affect the elasticity of a substance. Options A, B, and C are each individually correct but do not encompass the entire range of influences.