Spectroscopy

Question 1

Transition between electronic energy levels involves

Answer 1

UV/Vis radiation

Question 2

Transition between vibrational energy states involves

Answer 2

Infrared radtiation

Question 3

Transition between rotational energy levels involves

Answer 3

Microwave radiation

Question 4

UV/Vis representative frequency

Answer 4

10^15 Hz

Question 5

Infrared representative frequency

Answer 5

10^14 Hz

Question 6

Microwave representative frequency

Answer 6

10^11 Hz

Question 7

UV/Vis representative wavelength

Answer 7

Hundreds of nm

Question 8

Infrared representative wavelength

Answer 8

um range

Question 9

Microwave representative wavelength

Answer 9

mm range

Question 10

Direct electric dipole transitions are a result of

Answer 10

Interaction with EM radiation that is resonant with the separation between energy levels

Question 11

Ratio of degeneracies of electronic energy levels v=0 : v=1

Answer 11

1:1

Question 12

Ratio of degeneracies of vibrational energy levels v=0 : v=1

Answer 12

1:1

Question 13

Ratio of degeneracies of rotational energy levels v=0 : v=1

Answer 13

1:3

Question 14

Name the three processes given by the Einstein Model

Answer 14

Absorption, spontaneous emission, induced emission

Question 15

Absorption reaction equation

Answer 15

X + hv -> X*

Question 16

Spontaneous emission reaction equation

Answer 16

X* -> X + hv

Question 17

Induced emission reaction equation

Answer 17

X* + hv -> X + 2hv

Question 18

The rate of a transition process depends on

Answer 18

• number of molecules in the initial state
• rate coefficient of the transition
• spectral radiation density

Question 19

Define spectral radiation density

Answer 19

Concentration of photons interacting with matter

Question 20

Define transition moment

Answer 20

Size and direction of the transient change in the oscillating dipole moment accompanying the transition between two states

Question 21

What is the relationship between M and B, why is it important?

Answer 21

B = |M|^2

Shows that the transition moment is proportional to the probability of a transition occurring

Question 22

When is a transition allowed?

Answer 22

When M>0

Question 23

When is a transition forbidden?

Answer 23

When M=0