Dark line in an otherwise continuous bright spectrum, where light within one narrow frequency range has been removed.
Spectrum in which the radiation is distributed over all frequencies, except at a few specific frequencies. It is produce by light from a continuous spectrum source that passes through a low density gas. The gas absorbs the same frequencies that it would emit if heated.
Building block of matter, composed of positively charged protons and neutral neutrons in the nucleus, surrounded by negatively charged electrons.
The continuous spectrum emitted by a blackbody. The flux at each wavelength is given by a formula known as Planck's Law.
Broadening of spectral lines due to collisions between atoms, most often seen in dense gases.
Spectrum in which the radiation is distributed over all frequencies, not just a few specific frequency ranges. A prime example is the black-body radiation emitted by a hot, dense body.