UV Luminance Spectroscopy Why phosphorescence measurements are usually made at a low temperature? To decease the efficiency of detector To prevent thermal degradation of the phosphorescent species To promote phosphorescence by slowing the rate of radiationless transfer processes To increase the efficiency of the detector To decease the efficiency of detector To prevent thermal degradation of the phosphorescent species To promote phosphorescence by slowing the rate of radiationless transfer processes To increase the efficiency of the detector ANSWER DOWNLOAD EXAMIANS APP
UV Luminance Spectroscopy Internal conversion is where A molecule converts excess electronic energy to vibrational energy 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) None of these A molecule converts excess electronic energy to vibrational energy 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) None of these ANSWER DOWNLOAD EXAMIANS APP
UV Luminance Spectroscopy Why do fluorescence spectrometers often use double-beam optics? To compensate for beam attenuation by the monochromator To compensate for power fluctuations in the radiation source So a reference solution can be used All of these To compensate for beam attenuation by the monochromator To compensate for power fluctuations in the radiation source So a reference solution can be used All of these ANSWER DOWNLOAD EXAMIANS APP
UV Luminance Spectroscopy In the intersystem crossing All of these a molecule converts excess electronic energy to vibrational energy 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) All of these a molecule converts excess electronic energy to vibrational energy 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) ANSWER DOWNLOAD EXAMIANS APP
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 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 ANSWER DOWNLOAD EXAMIANS APP
UV Luminance Spectroscopy What is the relationship between wavelength and wave number? Wavelength in nanometers x wavenumber = 1 Wavenumber = 1 / wavelength in centimeters Wavenumber - wavelength in nanometers = 1 None of these Wavelength in nanometers x wavenumber = 1 Wavenumber = 1 / wavelength in centimeters Wavenumber - wavelength in nanometers = 1 None of these ANSWER DOWNLOAD EXAMIANS APP
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