Introduction to modern physics - FSU Physics Department

emission spectra
continuous spectrum
o solid, liquid, or dense gas emits continuous
spectrum of electromagnetic radiation
(“thermal radiation”);
o total intensity and frequency dependence
of intensity change with temperature
(Kirchhoff, Bunsen, Wien, Stefan,
Boltzmann, Planck)
line spectrum
o rarefied gas which is “excited” by heating,
or by passing discharge through it, emits
radiation consisting of discrete wavelengths
(“line spectrum”)
o wavelengths of spectral lines are
characteristic of atoms
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