Question

Raman spectroscopy is the result of what type of motion(s) in a molecular ensemble? a. For simple molecules, there is elastic and in-elastic scattering of photons, identify the name and describe the process

Elastic Raman scattering

Inelastic Raman scattering i

Of the two types of inelastic scattering, which type has the stronger intensity at room temperature? Why?

Answer 1

Raman spectroscopy is the result of molecular vibration in a molecular ensemble.

For simple molecules,there can be two types of scattering of Photons namely Rayleigh Scattering which is a type of elastic scattering and Stokes and Anti Stokes scattering which are a type of inelastic scattering.In Rayleigh scattering ,there is no change in frequency of incident light by frequency of molecular vibration.In inelastic scattering,there is some change in frequency of incident light due to molecular vibration,The increase in frequency is known as an Anti-Stokes shift and the decrease in frequency is known as a Stokes shift.

Of the two types of Inelastic Scattering,Stokes shifted Raman scattering is the most common at room temperature since the molecules are the ground state,hence they emit a photon of less energy than the incident photon's energy.