Quantum Raman (5)

Question 1

For Rayleigh scattering, what is the energy of incident monochromatic radiation?

Answer 1

hv0

Question 2

Upon Rayleigh scattering, what is the energy of the elastically scattered radiation?

Answer 2

hv0

Question 3

What is the change in the system for rayleigh scattering?

Answer 3

no change in energy

Question 4

What is the change in the system for raman scattering?

Answer 4

Change in energy = hv0

Question 5

Does a molecule gain or lose energy during Stokes Raman scattering?

Answer 5

gain

Question 6

From what initial energy level does stokes raman scattering occur?

Answer 6

ground

Question 7

In what final energy level does the molecule tend for stokes raman?

Answer 7

excited

Question 8

From where does the energy for the transition in Stokes Raman come?

Answer 8

annihilation of photon energy and simultaneous creation of photon with lower energy

Question 9

What is the energy of the photon after the Stokes inelastic collision?

Answer 9

Lower

Question 10

What is the energy of the molecule after the Stokes inelastic collision?

Answer 10

Higher

Question 11

Does a molecule gain or lose energy in Anti-stokes raman scattering?

Answer 11

lose

Question 12

from what initial energy level does anti-stokes raman scattering occur>

Answer 12

lower

Question 13

in what final energy level does the molecule end for anti?

Answer 13

higher

Question 14

From where does the energy for the anti-stokes raman scattering come>

Answer 14

inelastic collision energy transfers to incident photons

Question 15

What is the energy of the photon after the anti stokes inelastic collision?

Answer 15

hv0

Question 16

What is the energy of the molecule after the anti-stokes inelastic collision?

Answer 16

h(ṽ0 + ṽv)

Question 17

What are some of the common excitation wavelengths used in raman spectroscopy and their corresponding energies?

Answer 17

Argon (λ 488) E = 20,492
Argon (λ 514.5) E = 19,436
Krypton (λ 647.1) E = 15,453
He-Ne (λ 632.8) E = 15,802

Question 18

Why are raman spectra characterized by wavenumber shifts rather than absolute wavenumber?

Answer 18

ensures bands always plotted the same independent of particular laser excitation energy used in experiment

Question 19

How are wavenumber shifts calculated?

Answer 19

Δṽ’v = ṽ0 - ṽ’

Question 20

In what energy level do most molecules exist at room temperature?

Answer 20

ground

Question 21

How does the energy level at RT affect the intensity of the stokes vs anti-stokes bands?

Answer 21

stokes is much more intense

Question 22

How does the intensity distribution of anti-stokes raman bands change with increasing wavenumber away from the exciting line>

Answer 22

increases with increasing wavenumber

Question 23

Stokes vs Anti-stokes

Answer 23

stokes is in the ground state, anti-stokes starts in an excited state