UV Luminance Spectroscopy In the intersystem crossing a molecule converts its excess energy to light, and emits a photon a molecule converts excess electronic energy to vibrational energy All 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 All of these 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 phosphorescence measurements are usually made at a low temperature? 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 To increase the efficiency of the detector To decease the efficiency of detector To promote phosphorescence by slowing the rate of radiationless transfer processes 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 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 None of these Because the sample won't fluoresce if the incident radiation is of low power ANSWER DOWNLOAD EXAMIANS APP
UV Luminance Spectroscopy Fluorescence occurs when 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 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 a molecule lowers its vibrational energy by losing it's excess energy as a photon ANSWER DOWNLOAD EXAMIANS APP
UV Luminance Spectroscopy What is the relationship between wavelength and wave number? None of these Wavenumber - wavelength in nanometers = 1 Wavelength in nanometers x wavenumber = 1 Wavenumber = 1 / wavelength in centimeters None of these Wavenumber - wavelength in nanometers = 1 Wavelength in nanometers x wavenumber = 1 Wavenumber = 1 / wavelength in centimeters ANSWER DOWNLOAD EXAMIANS APP
UV Luminance Spectroscopy Why do fluorescence spectrometers often use double-beam optics? To compensate for power fluctuations in the radiation source All of these To compensate for beam attenuation by the monochromator 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 So a reference solution can be used ANSWER DOWNLOAD EXAMIANS APP
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