In gamma-decay a nucleus in an excited state decays to a lower energy state by the emission of a high energy photon called a gamma-ray.
A)Gamma-decay is always slow (greater than a ns).
B)Gamma-decay is always fast (less than a ns).
C)Gamma-decay is usually fast but can in special cases be slow.
D)Gamma-decay is always accompanied by the emission of a neutrino.
E)Gamma-decay is always accompanied by the emission of a $\beta$-particle.

Question

Quizplus · Accepted Answer

Gamma-decay is usually fast, with the lifetime of the excited state typically being on the order of picoseconds or less. However, in special cases where the nucleus is in a long-lived isomeric state, the gamma-decay can be slow, with a lifetime ranging from nanoseconds to minutes or even longer. Gamma-decay is not always accompanied by the emission of a neutrino or beta particle.

In Gamma-Decay a Nucleus in an Excited State Decays to a Lower