When light strikes an object, some wavelengths may undergo reflection or transmission, others are absorbed and their energy is converted to heat.

About absorption
  • When light is absorbed by an object or medium, its energy is transferred to electrons and emitted as heat.
  • Absorption of a particular wavelength of light into a material takes place when the frequency of the wave matches the frequency of electrons orbiting atomic nuclei.
  • Electrons selectively absorb photons with matching frequencies.
  • As electrons orbiting atomic nuclei absorb energy, they vibrate more vigorously causing atoms to collide with one which produces heat.
  • When light is reflected off a surface it bounces off at the same wavelength.
Related diagrams

Each diagram can be viewed on its own page with a full explanation.