Robert Bunsen

Atomic Spectra (Robert Bunsen)

For more than 200 years chemists have known that sodium salts produce a yellow color when added to a flame. Robert Bunsen, however, was the first to systematically study this phenomenon. (Bunsen went so far as to design a new burner that would produce a colorless flame for this work.) Between 1855 and 1860, Bunsen and his colleague Gustav Kirchhoff developed a spectroscope that focused the light from the burner flame onto a prism that separated this light into its spectrum. Using this device, Bunsen and Kirchhoff were able to show that the emission spectrum of sodium salts consists of two narrow bands of radiation in the yellow portion of the spectrum.