Chapter 17 - Fundamentals of Spectrometry

Question 1

1. Electromagnetic radiation is

2. Electromagnetic radiation have ____ like properties and ____ like properties

Answer 1

1. light

2. wave, particles

Question 2

Some properties of light are best described by thinking of it as a wave, while others are best at thinking it’s a particle.

Answer 2

Wave - Particle Duality

Question 3

Characterized a wave by its ______ and its _______

Answer 3

amplitude, wavelength

Question 4

Distance between successive peaks in a wave.

- expressed as unit of length - nanometers (10^-9)

Answer 4

wavelength

Question 5

the vertical height of the crest

- Determines the light’s ___ or ____

Answer 5

amplitude

- intensity, brightness

Question 6

Light is also characterized by ______

Answer 6

frequency

Question 7

Number of waves passing a fixed point in a given period of time.
- the units are cycles per second (1/s) or Hertz.

Wavelength and frequency are ______ related

Answer 7

frequency

inversely

Question 8

Something is quantized if it can have only particular values.

Plank’s constant(h):

Energy is ____ to frequency

Answer 8

quantization

6.626x10^-34 Js.

proportional

Question 9

As frequency (v) _____, Energy (E) ______

As wavelength (λ) ______, Energy (E) _____

Answer 9

increases, increases

decreases, increases

Question 10

the lowest energy state of a molecule

when a molecule absorbs a photon, the energy of the molecule ______
- the molecule is promoted to its _______

when a molecule emits a photon, the energy of the molecule ____ _____

Answer 10

ground state

increases
- excited state

lowered back down to ground state

Question 11

UV-Vis, absorption, excited they all increase and ____ _____

fluorescence, emission, emitted they all decrease and ______ ______

Answer 11

take in energy

releasing energy

Question 12

what happens when a molecule absorbs a photo?

Answer 12

Gets promoted to a higher energetic excited state

Question 13

This is an ______ _______ where an electron moves from one orbital to another.

Answer 13

electron transition

Question 14

If this electron has an opposite spin of it’s paired electron then it’s a _____ state.

If the electron has a parallel spin of it’s paired electron then it’s a _____ state.
- Triplet states are “_____” and are not _____ for every molecule.

Answer 14

singlet

triplet
-forbidden, observed

Question 15

_______ ______ _______ ________don’t have enough energy to cause an electronic transition.
- what motions they can change in a molecule?

So if a molecule undergoes an electronic transition, it is also undergoing ______ and _______ transitions as well.

Answer 15

infrared and microwave radiation
- vibrational and rotational motion

vibrational and rotational