Definition

1. Noun:
   • A spectrum of electromagnetic radiation emitted by a self-luminous source: An emission spectrum is the pattern of distinct lines or bands of light (electromagnetic radiation) produced when the atoms or molecules of a substance are excited (e.g., by heat or electrical energy) and then release that energy. Each element or compound has a unique emission spectrum, like a fingerprint.

Usage Examples

• Noun:
  • Scientists analyzed the star's composition by studying its emission spectrum.
  • The characteristic bright lines in the emission spectrum of hydrogen are visible through a spectroscope.
  • The gas tube glowed with a specific color, revealing its unique emission spectrum.

Advanced Usage

• "Continuous emission spectrum": A spectrum that shows an unbroken band of colors, emitted by hot, dense solids, liquids, or high-pressure gases.

  • An incandescent light bulb produces a continuous emission spectrum.

• "Line emission spectrum": A spectrum consisting of distinct, bright lines at specific wavelengths, emitted by hot, low-density gases.

  • The line emission spectrum of neon is used in brightly colored advertising signs.

Variants and Related Words

• Emission (n): The act of sending out light, heat, or other energy.

  • The emission of greenhouse gases is a major environmental concern.

• Spectrum (n): The entire range of wavelengths of electromagnetic radiation.

  • Visible light is just a small part of the electromagnetic spectrum.

• Absorption spectrum (n): The pattern of dark lines or bands in a spectrum, created when light passes through a cooler gas that absorbs specific wavelengths. This is the opposite of an emission spectrum.

Synonyms

• Bright-line spectrum: Another term for a line emission spectrum.
• Characteristic spectrum: Emphasizes that the spectrum is unique to a particular substance.

Related Phrases

• To produce an emission spectrum: To generate or create an emission spectrum.

  • Heating the element in a flame will cause it to produce an emission spectrum.

• To observe/record an emission spectrum: To view or document the spectrum.

  • The lab exercise required students to observe the emission spectrum of various salts.

Related Concepts

• Spectroscopy: The scientific study of spectra, including emission spectra, used to identify substances.

  • Emission spectroscopy is a key technique in analytical chemistry.

• Atomic spectrum: Often refers specifically to the line emission spectrum produced by excited atoms.

  • The atomic spectrum of mercury is used to calibrate spectrometers.

Noun

1. spectrum of electromagnetic radiation emitted by a self-luminous source