Definition

Noun: A line spectrum is an optical spectrum consisting of distinct, bright or dark lines at specific wavelengths, rather than a continuous band of colors. It is produced when atoms or ions in an excited state transition to a lower energy level, emitting or absorbing photons of very specific energies (and thus wavelengths).

Usage

A line spectrum is a fundamental concept in physics and chemistry, used to identify elements. * Scientists analyze the line spectrum of a star to determine its chemical composition. * The characteristic line spectrum of hydrogen includes a prominent red line. * In the laboratory, a spectroscope is used to observe the line spectrum emitted by a gas.

Advanced Usage

• Emission line spectrum: A spectrum showing bright lines against a dark background, created when excited atoms emit light.
  • The neon sign's glow, when passed through a prism, produces a distinctive emission line spectrum.
• Absorption line spectrum: A spectrum showing dark lines within a continuous spectrum, created when atoms absorb specific wavelengths from a background light source.
  • The Sun's spectrum is an absorption line spectrum, with dark Fraunhofer lines indicating elements in its outer atmosphere.

Variants and Related Words

• Spectrum (n): The entire range of wavelengths of electromagnetic radiation.
• Continuous spectrum (n): A spectrum that shows an unbroken sequence of colors or wavelengths, typically produced by hot, dense objects like solids or high-pressure gases. This contrasts with a line spectrum.
• Band spectrum (n): A spectrum consisting of groups of closely spaced lines, typically produced by molecules.

Synonyms

• Atomic spectrum
• Discrete spectrum

Antonyms

• Continuous spectrum

Related Phrases and Concepts

• Spectral line: An individual bright or dark line within a line spectrum.
  • Each spectral line corresponds to a specific electronic transition within an atom.
• To produce a line spectrum: The action of generating this type of spectrum.
  • Heating a sample of sodium in a flame will cause it to produce a characteristic yellow line spectrum.

Noun

1. a spectrum in which energy is concentrated at particular wavelengths; produced by excited atoms and ions as they fall back to a lower energy level