Answer:
Principle of flame photometry
Flame photometry relies upon the fact that:
· the compounds of the alkali and alkaline earth metals can be thermally dissociated in a flame and
· that some of the atoms produced will be further excited to a higher energy level.
When these atoms return to the ground state they emit radiation which lies mainly in the visible region of the spectrum. Each element will emit radiation at a wavelength specific for that element. The measurement of the emitted radiation forms the basis of flame photometry.