## nuclear level

https://doi.org/10.1351/goldbook.N04235
One of the energy values at which a @N04256@ can exist for an appreciable time ($$> 10^{-22}\ \text{s}$$).
Source:
PAC, 1982, 54, 1533. (Glossary of terms used in nuclear analytical chemistry (Provisional)) on page 1547 [Terms] [Paper]