Dave Shaffer's Astronomy Site
Here are pictures of the spectra of various gas discharge tubes. The long skinny discharge tubes, made of glass, are filled with whatever the gas of interest is. When connected to a several hundred volt power supply, the tubes light up, much in the manner of fluoroescent light bulbs. The excited gas atoms and molecules in the tubes emit light at certain wavelengths (the wavelengths depend on what gas it is). By noting the wavelengths, and comparing them with some standard - such as these photographs - the type of gas can be identified. These so-called "spectral lines" are unique to each gas, and depend on the quantuum mechanical details of the internal workings of the atoms and molecules.
These were used as references for unknown spectra which my students observed during an astronomy lab. For larger images, just click on the spectrum. You also can save it to a file on your computer. If you use these spectra, I'd appreciate an acknowledgement. THANKS! I can be e-mailed at firstname.lastname@example.org .
Spectra of Gas Discharge Tubes
Spectrum of a Hydrogen Gas Discharge Tube
Spectrum of a Helium Gas Discharge Tube
Spectrum of a Nitrogen Gas Discharge Tube
Spectrum of a Neon Gas Discharge Tube
Spectrum of a Mercury Gas Discharge Tube
Spectrum of a Xenon Gas Discharge Tube
Spectrum of a Krypton Gas Discharge Tube
Spectrum of an Argon Gas Discharge Tube