Analyzing The Emission Spectra of Sodium

The Chemistry of Art > 2. The Structure of the Atom and Colours > Analyzing The Emission Spectra of Sodium >

Gather and process information from secondary sources to analyse the emission spectra of sodium and present information by drawing energy level diagrams to represent these spectral lines


  • Symbol: Na
  • Atomic number: 11
  • Flame color: Yellow – Orange (visible region)
  • Wavelength of light emitted: 600 nm approx.
  • Ground state electron configuration: 1s22s22p63s1 

Spectra of sodium

  • Sodium burns with a bright yellowy-orange flame color which comes from the most frequent electron transition from excited state 3p energy level to 3s ground state level – emitting energy around yellow wavelength
  • Visible line spectrum is dominated by a closely spaced pair of yellow lines and appears as bright yellow doublet at approx 589 and 590nm
  • Doublet is a consequence of the different angular momentums possible for 3p electrons
  • By using CD as diffraction grating, the yellow colour can be commonly observed in street lamps.