Definition

Noun: 1. (Physics) A spectrum of radiation caused by electron transitions within an atom; the series of spectrum lines is characteristic of the element. * An atomic spectrum is the unique pattern of light (or other electromagnetic radiation) emitted or absorbed by the electrons of a specific chemical element when they change energy levels. This pattern appears as a series of distinct colored lines (emission lines) or dark lines (absorption lines) and serves as a "fingerprint" for that element.

Usage Examples

• Noun:
  • Scientists analyzed the atomic spectrum to identify the unknown gas in the tube.
  • The distinct atomic spectrum of hydrogen, with its specific series of lines, was key evidence for early quantum theory.
  • By comparing the observed atomic spectrum with known references, astronomers can determine the composition of distant stars.

Advanced Usage

• "to obtain/record an atomic spectrum": The process of capturing the spectral lines of an element using a spectroscope or spectrometer.
  • The lab exercise involved using a prism to obtain the atomic spectrum of sodium.
• "characteristic atomic spectrum": Emphasizes that the spectrum is a defining, unique property of an element.
  • Each element possesses a characteristic atomic spectrum that allows for its identification.

Variants and Related Words

• Emission spectrum (n): The spectrum of bright lines produced when an atom's electrons fall to lower energy levels and emit photons.
  • The neon sign glows with its characteristic red-orange emission spectrum.
• Absorption spectrum (n): The spectrum of dark lines produced when an atom's electrons absorb specific photons to jump to higher energy levels.
  • The sun's absorption spectrum reveals the elements present in its outer atmosphere.
• Line spectrum (n): A spectrum consisting of distinct, separate lines, as opposed to a continuous band of color. An atomic spectrum is a type of line spectrum.
  • Atomic gases produce a line spectrum, whereas incandescent solids produce a continuous spectrum.

Synonyms

• Characteristic spectrum: A spectrum that is typical of a particular substance.
• Line spectrum: A spectrum showing discrete lines corresponding to specific wavelengths.

Related Phrases

• Spectral lines: The individual lines (bright or dark) that make up an atomic spectrum.
  • The position of the spectral lines in an atomic spectrum corresponds to specific energy differences within the atom.

Noun

1. (physics) a spectrum of radiation caused by electron transitions within an atom; the series of spectrum lines is characteristic of the element