hot atom

https://doi.org/10.1351/goldbook.H02861
An atom in an excited energy state or having @K03402@ above the ambient thermal level, usually as a result of nuclear processes.
Source:
PAC, 1994, 66, 2513. (Nomenclature for radioanalytical chemistry (IUPAC Recommendations 1994)) on page 2520 [Terms] [Paper]