UV Luminance Spectroscopy Why do fluorescence spectrometers often use double-beam optics? 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 To compensate for power fluctuations in the radiation source 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 fluctuations in the dipole moment allow the molecule to deform by bending and stretching Because a change in dipole moment lowers the energy required for electronic transitions All of these Because for absorption to occur, the radiation must interact with the electric field caused by changing dipole moment Because fluctuations in the dipole moment allow the molecule to deform by bending and stretching Because a change in dipole moment lowers the energy required for electronic transitions All of these Because for absorption to occur, the radiation must interact with the electric field caused by changing dipole moment 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 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
UV Luminance Spectroscopy Why must the radiation source for fluorescence spectrometry be more powerful than for absorption spectroscopy? None of these To allow for scattering by the sample 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 None of these To allow for scattering by the sample 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 ANSWER DOWNLOAD EXAMIANS APP
UV Luminance Spectroscopy Fluorescence occurs when 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 None of these ANSWER DOWNLOAD EXAMIANS APP