UV Luminance Spectroscopy Why do fluorescence spectrometers often use double-beam optics? To compensate for beam attenuation by the monochromator So a reference solution can be used All of these To compensate for power fluctuations in the radiation source To compensate for beam attenuation by the monochromator So a reference solution can be used All of these To compensate for power fluctuations in the radiation source ANSWER DOWNLOAD EXAMIANS APP
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 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 To decease the efficiency of detector To prevent thermal degradation of the phosphorescent species ANSWER DOWNLOAD EXAMIANS APP
UV Luminance Spectroscopy In the intersystem crossing a molecule converts its excess energy to light, and emits a photon 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 excess electronic energy to vibrational energy a molecule converts its excess energy to light, and emits a photon 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 excess electronic energy to vibrational energy ANSWER DOWNLOAD EXAMIANS APP
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 for absorption to occur, the radiation must interact with the electric field caused by changing dipole moment All of these Because a change in dipole moment lowers the energy required for electronic transitions Because fluctuations in the dipole moment allow the molecule to deform by bending and stretching Because for absorption to occur, the radiation must interact with the electric field caused by changing dipole moment All of these Because a change in dipole moment lowers the energy required for electronic transitions Because fluctuations in the dipole moment allow the molecule to deform by bending and stretching ANSWER DOWNLOAD EXAMIANS APP
UV Luminance Spectroscopy What is the relationship between wavelength and wave number? Wavenumber = 1 / wavelength in centimeters Wavelength in nanometers x wavenumber = 1 Wavenumber - wavelength in nanometers = 1 None of these Wavenumber = 1 / wavelength in centimeters Wavelength in nanometers x wavenumber = 1 Wavenumber - wavelength in nanometers = 1 None of these ANSWER DOWNLOAD EXAMIANS APP
UV Luminance Spectroscopy Internal conversion is where 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) None 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) None of these ANSWER DOWNLOAD EXAMIANS APP
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