Question: In atomic fluorescence, the emission of electromagnetic radiation called resonance florescence occurs when the excitation wavelength is: 
 Options:  <1> 100 nm higher than the emission wavelength. <2> 100 nm lower than the emission wavelength. <3> Same as the emission wavelength. <4> 100 nm greater than the excitation wavelength. <5> 100 nm less than the excitation wavelength.
3