UV LUMINANCE SPECTROSCOPY QUIZ

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 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

Wavenumber = 1 / wavelength in centimeters

Wavenumber - wavelength in nanometers = 1

Wavelength in nanometers x wavenumber = 1

None of these

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

To increase the efficiency of the detector

To promote phosphorescence by slowing the rate of radiationless transfer processes

To prevent thermal degradation of the phosphorescent species

To decease the efficiency of detector

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)

a molecule converts excess electronic energy to vibrational energy

All of these

So a reference solution can be used

To compensate for power fluctuations in the radiation source

To compensate for beam attenuation by the monochromator

All of these

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