Index

Atoms
The Elements
Electron Energy Levels
Light Photons
Atomic Absorption Spectra
Atomic Emission Spectra
Stellar Spectra

Atomic Absorption Spectra

When a light passes through a cloud of gas, photons are absorbed. When the light is spread out as a spectrum, the missing photons show up as dark bands.

The above absorption spectrum was generated from white light that passed through oxygen gas. Most colours have passed through. Photons that cause electrons in oxgen atoms to jump to higher levels have been absorbed, causing the dark lines.