Dissemination of IT for the Promotion of Materials Science (DoITPoMS)



Quick questions

You should be able to answer these questions without too much difficulty after studying this TLP. If not, then you should go through it again!

  1. Which type of scattering results in a longer wavelength than the incident light?

    a Rayleigh
    b Stokes
    c Anti-Stokes

  2. Which type of scattering is the strongest?

    a Rayleigh
    b Stokes
    c Anti-Stokes

  3. Which of these properties must change for a mode to be Raman active?

    a Volume
    b Dipole moment
    c Polarisability

  4. Sulphur hexafluoride (SF6) is centrosymmetric. Which of these statements is true?

    Yes No a SF6 has an inversion centre.
    Yes No b SF6 obeys the rule of mutual exclusion.
    Yes No c Raman active modes will be IR active also.
    Yes No d IR active modes will be Raman inactive.
    Yes No e Modes will be Raman active if they involve a change in dipole moment.

  5. Can these alternative techniques be used to give a stronger signal than normal Raman spectroscopy?

    Yes No a Resonance Raman
    Yes No b Fourier transform Raman
    Yes No c Coherent Anti-Stokes Raman Spectroscopy
    Yes No d Stimulated Raman
    Yes No e Raman optical activity

Deeper questions

The following questions require some thought and reaching the answer may require you to think beyond the contents of this TLP.

  1. What advantages does Raman spectroscopy have for process monitoring?

  2. Calculate the wavenumber shift for the vibrational mode of Cl2, given that the force constant k for the bond is 3.23 N cm-1.