Nuclear reactions differ significantly from chemical reactions, primarily in how they affect the identity of elements involved. In chemical reactions, the number and type of atoms are conserved; for instance, if there are 5 atoms of carbon on the reactant side, there will also be 5 atoms of carbon on the product side. This conservation of mass and identity is a hallmark of chemical processes.

In contrast, nuclear reactions involve changes in the identity of elements due to alterations in the number of protons. While the overall mass number and the total number of protons remain conserved, the specific elements can transform into different ones. For example, if there are 5 protons on the reactant side, the product side will also have a total of 5 protons, but the elements themselves may change. This transformation is crucial in understanding processes such as radioactive decay, where the identity of the original element is altered as a result of nuclear reactions.