When the excited state of the daughter nuclide has a long half-life, the nuclides behave as what?

When the excited state of a daughter nuclide has a long half-life, these nuclides predominantly behave as pure gamma emitters. This occurs because, during the decay process, the parent nuclide transforms into the daughter nuclide, which may initially be in an excited state. If this excited state is stable for an extended period, the nuclide does not decay via particle emission (such as alpha or beta decay); instead, it primarily releases energy in the form of gamma radiation to transition to a lower energy state. This characteristic of long-lived excited states allows for significant gamma emission without the complications associated with other types of decay.

Efficiency in identifying these nuclides is important, as they can be critical in the context of medical applications, radiation safety, and understanding the behavior of isotopes in various environments. Their ability to remain in an excited state over longer periods leads to a more predictable and dominant emission of gamma rays compared to other decay processes.