Forensic Chemistry > 6. All elements have identifiable emission spectra and this can be used to identify trace elements > The Emission of Quanta of Energy >
Identify that the emission of quanta of energy as electrons move to lower energy levels may be detected by humans as a specific colour
Without the external source of energy, electrons fall back to their ground state, emitting quantized energy. The emitted quantum of energy is released in the form of a photon of light of characteristic frequency. This is seen as a colored line in the visible spectrum when the photon’s wavelength is between 400-750nm. For example, in high-voltage discharge tubes, various gases (e.g. neon) or vapours (e.g. sodium) are observed to emit light. The greater the intensity of the line, the more electrons falling and emitting radiation.