Final answer:
During radioactive decay, a parent isotope can gain or lose a neutron or a proton, resulting in the formation of a daughter isotope.
Step-by-step explanation:
During radioactive decay, a parent isotope can gain or lose a neutron or a proton and transform into a different element. This process produces a daughter isotope. For example, in alpha decay, a parent isotope emits an alpha particle (composed of two protons and two neutrons), resulting in a daughter isotope with two fewer protons and two fewer neutrons than the parent.