In
atomic spectroscopy, a very narrow band of frequencies of
electromagnetic radiation emitted or absorbed by atoms, which undergo a single
electronic transition.
Notes: - The radiation is centred on a peak whose wavelength characterizes the line and which corresponds to the emission or absorption maximum.
- A distinction is made between lines corresponding to transition of neutral atoms (e.g., \(\ce{Ba I}\ \pu{553.548 nm}\) and \(\pu{577.762 nm}\)) and ions (e.g., \(\ce{Ba II}\ \pu{455.403 nm}\)).
Source:
PAC, 2021, 93, 647. 'Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)' on page 734 (https://doi.org/10.1515/pac-2019-0203)