Chapter 17 - Fundamentals of Spectrometry Flashcards
- Electromagnetic radiation is
2. Electromagnetic radiation have ____ like properties and ____ like properties
- light
2. wave, particles
Some properties of light are best described by thinking of it as a wave, while others are best at thinking it’s a particle.
Wave - Particle Duality
Characterized a wave by its ______ and its _______
amplitude, wavelength
Distance between successive peaks in a wave.
- expressed as unit of length - nanometers (10^-9)
wavelength
the vertical height of the crest
- Determines the light’s ___ or ____
amplitude
- intensity, brightness
Light is also characterized by ______
frequency
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
frequency
inversely
Something is quantized if it can have only particular values.
Plank’s constant(h):
Energy is ____ to frequency
quantization
6.626x10^-34 Js.
proportional
As frequency (v) _____, Energy (E) ______
As wavelength (λ) ______, Energy (E) _____
increases, increases
decreases, increases
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 ____ _____
ground state
increases
- excited state
lowered back down to ground state
UV-Vis, absorption, excited they all increase and ____ _____
fluorescence, emission, emitted they all decrease and ______ ______
take in energy
releasing energy
what happens when a molecule absorbs a photo?
Gets promoted to a higher energetic excited state
This is an ______ _______ where an electron moves from one orbital to another.
electron transition
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.
singlet
triplet
-forbidden, observed
_______ ______ _______ ________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.
infrared and microwave radiation
- vibrational and rotational motion
vibrational and rotational
