nuclear isomer
Technical term in nuclear physics for a metastable state of an atomic nucleus. Often contrasted with 核異性体 (nuclear isomer as a substance).
See also: 核異性体
A nuclear isomer refers to a metastable state of an atomic nucleus in an excited state.
The decay process of a nuclear isomer can differ from ordinary radioactive decay.
Compound of 異性 (isomerism, from 異 'different' + 性 'property') and 核 (nucleus). The exact historical derivation is uncertain; the term is a modern technical coinage.