Pocket Slides

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Pocket Slides

• Introduction to Nanotechnology

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Atomic Interactions with Light

• Knowing the structure of atoms tells us about
  their
• Chemical properties
• Material properties
• Light-emitting and absorbing properties
• From this information we can make estimates of
  predictions about how a material will behave, and
  how it will interact with EM energy

An example of absorption spectra from many
different types of stars.
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Electromagnetic Spectrum

• Classifications, from lowest to highest energy
• radio, micro, IR, visible 400nm to 750 nm, UV,
  X-ray, and gamma
• Visible spectrum
• ROY G BIV (red, orange, yellow, green, blue,
  indigo and violet)
• Photon energy equation
• E h? hc/?
• The energy of a photon is related to its
  frequency and wavelength
• If an electron absorbs energy equal to the
  difference between its current level and that of
  an available higher level, it will jump to the
  higher level, excited state
• The same electron can then drop to a lower energy
  level (by 1 level or more), emitting a photon,
  equal in energy to the difference between the
  levels
• Emission versus absorption spectra
• Emission spectra produce a unique fingerprint of
  bright lines the result of passing light
  produced by photon emission through a prism
• Absorption spectra produce a unique fingerprint
  of dark lines the result of an elements
  absorption of certain photons of white light