Intro to Spec
This technique studies how light interacts with matter to determine its concentration or identity.
What is spectrophotometry?
The energy of a photon is given by this equation.
What is E = hv?
What does EMR stand for in spectroscopy?
Electromagnetic Radiation
What type of electromagnetic waves are X-rays in terms of wavelength?
Very short wavelength (0.01–100 Å)
What does XAS mainly study?
How X-rays interact with atoms in materials
The amount absorbed when light hits a sample and some passes through.
What is absorbance?
Increasing frequency of light increases this property.
What is photon energy?
What are the two behaviors of light described in EMR?
Wave-like and particle-like behavior
What happens when waves undergo constructive interference?
They reinforce each other, creating bright regions (maxima)
What does an absorption edge represent in XAS?
The specific energy where an element absorbs X-rays
This type of spectrophotometry measures how much light is absorbed by a solution at a specific wavelength.
What is UV-Vis Spectrophotometry?
The wave property of light that explains why metals emit electrons when exposed to UV radiation.
What is wave-length?
What happens to frequency when wavelength increases?
Frequency decreases
What is the main difference between constructive and destructive interference?
Constructive = waves add up; Destructive = waves cancel out
How does XAS help identify elements?
Each element absorbs X-rays at unique energies
The relationship between absorbance and concentration is described by this law.
What is Beer-Lambert Law?
The energy of a proton directly proportional to this property.
What is frequency?
The color of light with the longest wavelength in the spectrum.
What is the process called when electrons slow down in an X-ray tube producing radiation?
Bremsstrahlung
What does “chemical sensitivity” in XAS mean?
It detects small changes in an atom’s chemical environment (bonding/structure)
The part of a spectrophotometer that isolates a specific wavelength of light.
What is a monochromator?
The equation E = h x v expresses this relationship.
What is the Planck's Equation?
The shortest wavelength and highest energy region of the spectrum.
What are gamma rays?
Why do X-rays have the ability to interact with atomic structures?
Because they have very high energy and very short wavelength, allowing them to penetrate and interact with atoms
Why is XAS considered a powerful tool for material analysis?
Because it provides detailed information about atomic structure, bonding, and composition even in complex materials