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

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

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UV Luminance Spectroscopy
Internal conversion is where

A molecule converts excess electronic energy to vibrational energy
None of these
A molecule converts its excess energy to light, and emits a photon
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 increase the efficiency of the detector
To prevent thermal degradation of the phosphorescent species
To decease the efficiency of detector
To promote phosphorescence by slowing the rate of radiationless transfer processes

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UV Luminance Spectroscopy
In the intersystem crossing

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

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UV Luminance Spectroscopy
For a molecule to absorb IR, why must the molecule's vibrations cause fluctuations in the dipole moment of the molecule?

Because a change in dipole moment lowers the energy required for electronic transitions
Because for absorption to occur, the radiation must interact with the electric field caused by changing dipole moment
All of these
Because fluctuations in the dipole moment allow the molecule to deform by bending and stretching

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