Use a spectrometer to measure the spectral lines of sodium and mercury lamps. The spacing of the diffraction grating is calculated using:


  • Describe how different gases produce different emission lines.
  • Learn how to use a spectrometer.
  • Understand interference and perform calculations using:

Links to Stage 6 Physics Syllabus Content

PH12-14/Light: Wave Model

  • Conduct investigations to analyse quantitatively the interference of light using double slit apparatus and diffraction gratings. (ACSPH116, ACSPH117, ACSPH140).
  • Analyse the experimental evidence that supported the models of light that were proposed by Newton and Huygens. (ACSPH050, ACSPH118, ACSPH123).

PH12-15/Origins of the Elements

  • Conduct investigations to analyse qualitatively the diffraction of light. (ACSPH048, ACSPH076).
  • Account for the production of emission and absorption spectra and compare these with a continuous black body spectrum (ACSPH137).