UV Luminance Spectroscopy Why phosphorescence measurements are usually made at a low temperature? To increase the efficiency of the detector To promote phosphorescence by slowing the rate of radiationless transfer processes To decease the efficiency of detector To prevent thermal degradation of the phosphorescent species To increase the efficiency of the detector To promote phosphorescence by slowing the rate of radiationless transfer processes To decease the efficiency of detector To prevent thermal degradation of the phosphorescent species ANSWER DOWNLOAD EXAMIANS APP
UV Luminance Spectroscopy What is the relationship between wavelength and wave number? Wavenumber = 1 / wavelength in centimeters Wavenumber - wavelength in nanometers = 1 Wavelength in nanometers x wavenumber = 1 None of these Wavenumber = 1 / wavelength in centimeters Wavenumber - wavelength in nanometers = 1 Wavelength in nanometers x wavenumber = 1 None of these ANSWER DOWNLOAD EXAMIANS APP
UV Luminance Spectroscopy Fluorescence occurs when a molecule returns to the electronic ground state from an excited triplet state by losing it's excess energy as a photon a molecule returns to the electronic ground state from an excited singlet state by losing it's excess energy as a photon None of these a molecule lowers its vibrational energy 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 a molecule returns to the electronic ground state from an excited singlet state by losing it's excess energy as a photon None of these a molecule lowers its vibrational energy by losing it's excess energy as a photon ANSWER DOWNLOAD EXAMIANS APP
UV Luminance Spectroscopy In the intersystem crossing 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 All 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 All of these ANSWER DOWNLOAD EXAMIANS APP
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) A molecule converts its excess energy to light, and emits a photon 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 A molecule converts excess electronic energy to vibrational energy 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 magnitude of the output signal is proportional to the power of the incident radiation Because the sample won't fluoresce if the incident radiation is of low power To allow for scattering by the sample None of these Because the magnitude of the output signal is proportional to the power of the incident radiation Because the sample won't fluoresce if the incident radiation is of low power To allow for scattering by the sample ANSWER DOWNLOAD EXAMIANS APP
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