1.  Definition of Spectrum
     what are the colors in the visible spectrum? (ROYGBIV)
     How do we see white?   (a surface that reflects all colors of light)
           This is the opposite for paints!  (pigments)
     What is black?   A surface that does not reflect any colors of light

2.  The black box is called a spectrometer.
Parts:   narrow end,  broad end.  spectromet grating,  numbers, tiny vertical slot.
 

3.  Viewing an incandescent light source:
Learn how to use the spectrometer
hold it horizontally - eye to the narrow end - look straight thru the box out the tiny vertical slot directly at the light source
When you can see the light source through the tiny vertical slot,  don't move the box, but look with your eye to the right side of the box.... you will see a spectrum of colors,  and also a small row of numbers above the colors.

Have students describe what they see....  it should look something like this:
 
 

4.  Viewing a flourescent light source

Keep the incandescent bulb lit, and at the same time provide a flourescent light source.  Have the student view one and then the other.   Describe the differences they see.

Flourescent light looks something like this:
 
 

5.  How do flourescent lights work?   A gas inside a glass tube... add electricity... the gas glows. (the simplified version - ignores the very important function of the coating).

When gases glow they emit light - but not all colors of light.   So a few colors are missing in it's spectrum.

Incandescent bulbs produce a 'Continuous spectrum'.
Flourscent lights produce a spectrum with certain wavelengths missing.
 

6.  Viewing the spectra of other gases.
If available, discharge other gas specturm tubes.  Have students view these one at a time, first with their eyes and tell what colors they see, then with the spectrometers and tell what color lines they see.
 

7.  Spend some time having students record the spectral lines they observe on paper.  Use