Such nuclei have half-lives that are more easily measurable, and some rare nuclear isomers are able to stay in their excited state for minutes, hours, days, or occasionally far longer, before emitting a gamma ray.
Such nuclei have half-lives. These lives are more easily measurable. Some rare nuclear isomers are able to stay in their excited state for minutes, hours, days, or occasionally far longer. This was before emitting a gamma ray.