When this complex absorbs light, it immediately returns to the fundamental state without emitting any photons. This type of complex is called static quenching and it can be described with the following equations: The extent of quenching depends on the nature of the quencher molecule (fluorophore or non-fluorophore), the type of interaction, and the wavelength of energy that is emitted by the fluor. It may occur due to various factors like pH, temperature, viscosity, complex formation. The order of quenching efficiency is G