Of-7 Absorption Lines of Sodium
Published: Wednesday 15 March 2006 - Updated: Monday 28 March 2011
To demonstrate that sodium vapour absorbs wavelengths equal to its emission spectra.
- Sodium Spectral lamp
- Bunsen Burner
- Slide Projector
- Wire Gauze
- Table Salt
- 2 Lab Jacks
- Transmission Diffraction Grating
- Flexicam camera and monitor
Click on pictures to enlarge.
Sodium Absorption Lines
A white light source from a slide projector is directed onto a high quality diffraction grating located on the prism table of the student spectrometer. A continuous spectrum is displayed on the monitor. A bunsen burner located directly in front of the entrance slit of the spectrometer heats a wire grid that has been coated with table salt. The distinct dark absorption lines of sodium appear in the yellow region of the visible spectrum.