Revisit the experiment, the competing explanation and the evidence that changed the argument.
Robert Bunsen and Gustav Kirchhoff identified cesium in 1860 and rubidium in 1861 through spectroscopy.
How can an unfamiliar line suggest another element?
THE CHEMICAL CONNECTION
A prism separates emitted light into spectral lines. Those patterns can distinguish samples. Identifying a constituent does not require isolating its metal.
Use qualitative blue and red line markers. Their placement, brightness and width are illustrative; no wavelength values or historical intensities are supplied.
Optional: check your understanding
MAKE THE CONNECTION
An unfamiliar line appears in a mineral extract. Which next step would best strengthen the interpretation?