Absorption spectra

Electron shells of metal atoms in the gas phase can be elevated to an excited state by light. If light is passed through the metal vapour, various lines will be absent from its spectrum afterwards. These lines correspond to the energy levels of those electrons in the metal vapour which have been excited by the light. Spectra such as this are called absorption spectra. This experiment investigates absorption spectra of the following metals: strontium, barium, calcium, sodium, lithium, potassium, platinum, cobalt and magnesium.

Tasks

Record the absorption spectra of the metal salts and calculate the wavelengths λ.

What you can learn about

• Bohr atom
• Absorption bands
• Electron gas