The solution containing the relevant substance to be analysed is drawn into the burner and dispersed into the flame as a fine spray. The solvent evaporates first, leaving finely divided solid particles which move to the hottest region of the flame where gaseous atoms and ions are produced through the dissociation of molecules. Here electrons are excited as described above, and the spontaneously emit photon to decay to lower energy states. It is common for a monochromator to be used to allow for easy detection.