There should be seven gas samples in the carousel: hydrogen, helium, nitrogen, neon, argon, carbon dioxide, and air. To move from one sample to the next, carefully rotate the middle part of the carousel until the next sample clicks into position.

NOTE: Turn off the spectrum carousel when you are not actively viewing a gas sample. The gas samples will burn out after extended use, particularly the hydrogen sample, which has a useful lifetime of approximately 40 hours.

1. Begin by observing the spectra of hydrogen and helium. Note the wavelength and intensity of the emission lines in each spectrum in your worksheet. You will need to devise a way of describing the intensity, or strength, of the individual lines.
    
2. Measure the spectra of neon and argon and observe the colors they make when discharging. Can you explain why these two gases glow with the colors they do?
    
3. Observe the spectra of nitrogen, carbon dioxide, and air. These gases will have complicated emission spectra with many lines. Can you determine which of the other gases are present in air by examining its spectral lines?
    
4. Measure the spectrum of the flourescent lights in the ceiling. If your lab is during the day, measure the spectrum of the sun by pointing the fiber optic cable out the window. Can you determine which elements are producing the spectral lines in these sources?

Hints:

• When viewing a sample, you may need to slightly adjust the fiber optic cable mount or the rotation of the carousel in order to line up the sample and get a good reading.
• You can freeze the spectrum graph in SpectraSuite in order to take detailed readings by clicking on the spectrum chart and pressing the pause button.