UV Luminance Spectroscopy Why phosphorescence measurements are usually made at a low temperature? To increase the efficiency of the detector To decease the efficiency of detector 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 To promote phosphorescence by slowing the rate of radiationless transfer processes To prevent thermal degradation of the phosphorescent species ANSWER DOWNLOAD EXAMIANS APP
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 To compensate for beam attenuation by the monochromator All of these So a reference solution can be used To compensate for power fluctuations in the radiation source To compensate for beam attenuation by the monochromator All of these ANSWER DOWNLOAD EXAMIANS APP
UV Luminance Spectroscopy Internal conversion is where A molecule converts excess electronic energy to vibrational energy 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 None of these A molecule converts excess electronic energy to vibrational energy 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 None of these ANSWER DOWNLOAD EXAMIANS APP
UV Luminance Spectroscopy Why must the radiation source for fluorescence spectrometry be more powerful than for absorption spectroscopy? None of these Because the sample won't fluoresce if the incident radiation is of low power To allow for scattering by the sample 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 Because the magnitude of the output signal is proportional to the power of the incident radiation ANSWER DOWNLOAD EXAMIANS APP
UV Luminance Spectroscopy What is the relationship between wavelength and wave number? Wavenumber = 1 / wavelength in centimeters None of these Wavelength in nanometers x wavenumber = 1 Wavenumber - wavelength in nanometers = 1 Wavenumber = 1 / wavelength in centimeters None of these Wavelength in nanometers x wavenumber = 1 Wavenumber - wavelength in nanometers = 1 ANSWER DOWNLOAD EXAMIANS APP
UV Luminance Spectroscopy In the intersystem crossing All of these a molecule converts its excess energy to light, and emits a photon a molecule converts excess electronic energy to vibrational energy the spin of an excited electron reverses, changing the state of the molecule (from singlet state to triplet state or vice versa) All of these a molecule converts its excess energy to light, and emits a photon a molecule converts excess electronic energy to vibrational energy the spin of an excited electron reverses, changing the state of the molecule (from singlet state to triplet state or vice versa) ANSWER DOWNLOAD EXAMIANS APP
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