noun

• A series of lines in the infrared spectrum of atomic hydrogen, between 1.88 and 0.82 micrometres.

  ‘The Paschen series describes transitions from a higher level down to n = 3.’

  More example sentences

  • ‘See a 1922 paper by Frederick Brackett comparing Bohr's formula for the hydrogen spectral series with the Paschen series and with two members of a new series.’