Spectroscopy Activity

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COLORS OF THE SUN

• Spectroscopy Activity
• http//solar-center.stanford.edu/activities/cots.h
  tml

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What is Spectroscopy?
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Build a Spectroscope
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1. Cut out pieces fold

• Cut along all of the red lines to separate the
  pieces of the spectroscope. You should now have 8
  pieces
• Spectroscope body
• Gap Edge
• Spacers(2)
• Diffraction Grating
• Eyepiece
• Numbered Scale
• Scale Cover
• Write your name on the colored side of the
  spectroscope body where it say This spectroscope
  belongs to

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2. Assemble Spectroscope Body

• With the black side up, use a straight edge to
  crease the spectroscope body along each of the
  grey dashed lines. Then fold the spectroscope
  body closed (with black side in). Put flap B over
  flap A so they overlap and tape edge as shown

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3. Form wide scale side of Spectroscope

• On the wide, open side there are two long flaps
  labeled flap C and flap D. Fold down flap D then
  fold down flap C over it. Tape flap C as shown.
  Then fold down the small end tab and tape corners
  as shown.

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4. Finish end of spectroscope

• Fold down the end tabs, then fold Flap C down
  over the end tabs as shown. Tape the corners of
  the end as shown.

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5. Make entrance slit

• Light must enter the spectroscope through a gap
  formed between flap C and the gap edge. The gap
  is called the entrance slit. READ CAREFULLY it
  is important for the gap to be straight and
  narrow, so you will need to use the spacers.
  Stack both spacers and sandwich them between flap
  C and the gap edge as shown. Hold the gap edge
  tight against the spacers and tape on the
  spectroscope. Then remove the spacers from the
  gap. You should be able to see through the slit
  and it should be two thicknesses of the poster
  paper. Note the slit will be a little
  off-center but this is O.K.

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6. Align attach grating and eyepiece

• At the narrow end of the spectroscope, fold the
  end tabs to form a square opening and tape as
  shown. Next, cover the square opening with the
  diffraction grating. Before taping, make sure
  your diffraction grating is aligned so that the
  word Warning is facing out and cover the
  Warning on the bottom end tab. Tape the
  correctly aligned grating securely in place.
  Tape the eyepiece over the grating with the
  Warning aligned.

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7. Position scale

• Place the numbered scale so it covers the open
  side of the spectroscope. When viewed through
  the eyepiece, the 3000 end should be closest to
  the slit. DO NOT TAPE UNTIL STEP 8. Holding the
  scale in place while looking through the
  eyepiece, aim the spectroscope so you can see a
  fluorescent light through the slit. (It must be a
  fluorescent light, an incandescent light bulb
  will not work) You will se colored lines on the
  scale these are spectral lines. If the
  spectral lines appear above the slit instead of
  over the scale, rotate the diffraction grating ¼
  turn.

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8. Calibrate spectroscope

• Slide scale back and forth until dashed line at
  5450Å is aligned with green spectral line from
  fluorescent lamp. The tape scale in place.
  Finally place scale cover over the scale and tape
  it only along the top edge. That way you can
  lift the scale cover if it is too dark to read
  the scale.

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Congratulations!

• Your spectroscope is fully operational. Look at
  various sources of light with your spectroscope.
  NEVER LOOK DIRECTLY AT THE SUN. (and if you do,
  dont do it with your remaining eye)

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Activities

• Look at various sources of light and draw the
  spectrum that you see on the provided worksheet.
• Some suggestions are
• Fluorescent lamps
• Light bulbs
• TVs or computers
• A white object in sunlight
• A colored object in sunlight
• The Moon

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Appendix A Sample Spectra

• Solar
• Hydrogen
• Helium
• Sodium
• Calcium
• Mercury
• Neon
• Argon
• Water

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Appendix B How does it work?
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Appendix C What is diffraction?