line radiation
Quick Summary
Line radiation refers to electromagnetic radiation emitted or absorbed at specific, discrete wavelengths. This occurs when an ion, atom, or molecule transitions between distinct energy levels. In emission, energy is released as a photon when moving to a lower energy state, creating bright lines in a spectrum. In absorption, a photon is taken in to move to a higher energy state, creating dark lines.123
The most well-known example is the hydrogen atom's spectral lines, which are precisely measured and calculated using quantum mechanics. These lines are crucial in astronomy for identifying elements and understanding celestial objects, such as the 21-centimeter line emitted by neutral hydrogen.124
Ask Britannica AI about this topic
Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.
