Final answer:
Gamma emission in this case results in the conversion of 22890Th to 22891Pa without changing the nucleus's fundamental properties. Hence, option (b) is correct.
Step-by-step explanation:
The resulting nucleus from the gamma emission of 22890Th is 22891Pa, which is option (b) in the given choices. Gamma emission is a type of radioactive decay that occurs when an excited nucleus releases energy in the form of a gamma ray photon, without any change in the atomic number or atomic mass of the nucleus.
The emitted gamma ray carries away excess energy from the nucleus, leading to its transition to a more stable state. This phenomenon is crucial in understanding nuclear reactions, providing insights into the behavior of atomic nuclei during decay processes. In this case, the gamma emission converts the parent nucleus of 22890Th to the daughter nucleus of 22891Pa.