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

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

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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 fluctuations in the dipole moment allow the molecule to deform by bending and stretching
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

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UV Luminance Spectroscopy
Internal conversion is where

A molecule converts excess electronic energy to vibrational energy
None of these
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 its excess energy to light, and emits a photon

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UV Luminance Spectroscopy
Fluorescence occurs when

a molecule lowers its vibrational energy by losing it's excess energy as a photon
None of these
a molecule returns to the electronic ground state from an excited singlet state by losing it's excess energy as a photon
a molecule returns to the electronic ground state from an excited triplet state by losing it's excess energy as a photon

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

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

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