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Question 1

what is spectroscopy based on?

Answer 1

when light is shined on a molecule, it can transition between energy states through absorption and fall back down through emission, these correspond to the peak observed

Question 2

what is the peak in a spectrum?

Answer 2

it corresponds to a transition between energy levels

Question 3

for an electronic transition, what light is required

Answer 3

UV/Visible

Question 4

for vibrational transitions, what light is required

Answer 4

infared

Question 5

for rotational transitions, what light is required

Answer 5

microwave light

Question 6

what type of transition requires the highest energy light

Answer 6

electronic transitions

Question 7

what type of transition requires the lowest energy light?

Answer 7

rotational transitions

Question 8

what is lifetime broadening

Answer 8

in quantum mechanics, the excited state will only stay excited for so long before returning to ground state

Question 9

for lifetimebroading how are ∆E and ∆t related

Answer 9

they are inversely related

Question 10

if the lifetime broadening is big (long lifetime) what happens to ∆E

Answer 10

it is small (there will be a narrow peak)

Question 11

if the lifetime broadening is small (short lifetime) what happens to ∆E

Answer 11

it is big (there will be a broad peak)

Question 12

what is pressure/collisional broadening

Answer 12

in a collision, an excited state molecule can transfer its energy to another molecule and come back down to the ground state

Question 13

how do collisions affect the excited state lifetime

Answer 13

the time between collisions affects the lifetime