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SPECTROSCOPY

SPECTROSCOPY. Fascinating Light. Fireworks Various colors Due to atomic spectra of various elements Na (yellow), Sr (red), Ba (blue) Light transmitted through space Aurora borealis or “Northern Lights” Light transmitted through space.

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SPECTROSCOPY

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  1. SPECTROSCOPY

  2. Fascinating Light Fireworks Various colors Due to atomic spectra of various elements Na (yellow),Sr (red),Ba (blue) Light transmitted through space Aurora borealisor“Northern Lights” Light transmitted through space http://www.fireworks-london.co.uk/images/template_5_06.jpg http://www.geofffox.com/MT/images/Northern-Lights-large.jpg
  3. Spectroscopy The science that deals with the interactions of electromagnetic radiation (EMR) or light with matter Electromagnetic radiation(EMR) - or simply light, is energy traveling through space.
  4. Light = Electromagnetic Radiation Electric field Magnetic field http://static.flickr.com/35/121582712_5c0f8d193a_m.jpg http://www.cs.cornell.edu/People/egs/magnetos/friends.html
  5. In vacuum, EM waves travel at a constant speed of 3.00 x 108 m/s
  6. High energy Low energyHigh frequency Low frequencyShort wavelength Long wavelength Image available at herschel.jpl.nasa.gov
  7. Visible light, the light that we see with our eyes, is only a small portion of the EM spectrum - Associated with rainbow colors
  8. A Continuous Spectrum A prism can break white light up into the visible light spectrum, resulting into a continuous spectrum. Here the spectrum shows a smooth transition between colors (or wavelengths). Continuous spectrum Image available at http://solarsystem.nasa.gov/deepimpact/science/spectroscopy.cfm
  9. A Line Spectrum When a gaseous element is heated to its excited state, it emits light (wavelengths) in discrete patterns called a line spectrum Image available at http://ausgo.aao.gov.au/IYAcontest/news.html
  10. Fascinating Light Fireworks Light transmitted through space Basically show the emission spectra of various elements in firework mixture Image available at http://www.fireworks-london.co.uk/images/template_5_06.jpg
  11. Examples of everyday life spectroscopy(matter-light interaction) Matter Light (EMR) Effect Suntan UV light Tans or burns skin Chlorophyll visible light Synthesis of food Tuning circuits radiowaves Produces sound
  12. Amount of Light Absorbed Related to Concentration The higher the absorbance (A), the higher is the amount or concentration of substances (ex. blue dye) in solution We can use a spectrometer, measure absorbance and calculate the amount of blue dyein solution
  13. A SPECTROMETER NOTE: This process only works for colored solutions. Spectrometer image available at: http://www.cofc.edu/~kinard/
  14. Amount of Light Absorbed Related to Concentration The higher the absorbance (A), the higher is the amount or concentration of substances (ex. blue dye) in solution We can use a spectrometer, measure absorbance and calculate the amount of blue dyein solution How exactly is absorbance related to concentration?
  15. Use of Standards in Measurements What do we need to measure its length? How long is the object in this picture?
  16. Use of Standards in Measurements The ruler is a standard used for measuring length. Blue dye standard solutions are used for measuring the amount of blue dye in commercial drinks.
  17. How much blue dye is in Gatorade? Use a spectrometer Measure absorbance of light, A Compare with A of known amounts or concentrations of blue dye (called blue dyestandards) Each blue dye standard has a fixed amount of blue dye Much like each scale in a ruler --- has a fixed measurement) Create a graph of A versus known amount of blue dye standards = Standard Curve Using A of sample (ex. Gatorade) with unknown amount of blue dye, extrapolate to determine amount of blue dye in sample
  18. Absorbance and concentrations of blue dyestandards
  19. A Sample ppm blue dye in sample x
  20. Percent (%) vs. Parts-per-million (ppm) or simply ppm = % x 10,000 Toxic gas; lethal level in ppm scale Percent = parts per hundred (pph)Parts-per-million = one part in a million parts (ppm)
  21. A Sample ppm blue dye in sample x
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