UV Luminance Spectroscopy
Why do fluorescence spectrometers often use double-beam optics?

So a reference solution can be used
To compensate for beam attenuation by the monochromator
To compensate for power fluctuations in the radiation source
All of these

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UV Luminance Spectroscopy
In the intersystem crossing

a molecule converts its excess energy to light, and emits a photon
a molecule converts excess electronic energy to vibrational energy
All of these
the spin of an excited electron reverses, changing the state of the molecule (from singlet state to triplet state or vice versa)

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UV Luminance Spectroscopy
Why phosphorescence measurements are usually made at a low temperature?

To decease the efficiency of detector
To increase the efficiency of the detector
To prevent thermal degradation of the phosphorescent species
To promote phosphorescence by slowing the rate of radiationless transfer processes

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UV Luminance Spectroscopy
Internal conversion is where

the spin of an excited electron reverses, changing the state of the molecule (from singlet state to triplet state or vice versa)
None of these
A molecule converts excess electronic energy to vibrational energy
A molecule converts its excess energy to light, and emits a photon

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UV Luminance Spectroscopy
Why must the radiation source for fluorescence spectrometry be more powerful than for absorption spectroscopy?

To allow for scattering by the sample
None of these
Because the sample won't fluoresce if the incident radiation is of low power
Because the magnitude of the output signal is proportional to the power of the incident radiation

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