spectral line

American  

noun

Optics.

1. a line in a spectrum due to the absorption or emission of light at a discrete frequency.

---

spectral line Scientific  

/ spĕk′trəl /

1. An isolated bright or dark line in a spectrograph produced by emission or absorption of light of a single wavelength, generally corresponding to a specific shift in the energy of an electron moving from one orbital to another.

---

Etymology

Origin of spectral line

First recorded in 1865–70

Example Sentences

A spectral line is a dark or bright line within a continuous spectrum.

From Science Daily • Feb. 29, 2024

“The ‘hydrogen line’ is the electromagnetic radiation spectral line that is created by a change in the energy state of neutral hydrogen atoms.

From Washington Post • Jun. 20, 2019

Could you tell what element that spectral line comes from?

From Textbooks • Oct. 13, 2016

It was tracked for 72 seconds and had a frequency similar to that of the spectral line for hydrogen.

From Time • Mar. 20, 2015

If care is not taken, the dust and irregularities of the film will give trouble, each foreign particle appearing as a fine spectral line.

From Scientific American Supplement, No. 601, July 9, 1887 by Various