Science Buddies: "Ask an Expert"

Hi we are working on a 6th grade science project. We have built a simple spectroscope, with a DVD
and have tested various light bulbs, incandescent, florescent, black light, led,and halogen and have photographed
each result. It looks good, we just don't know how to interpret it. We have conflicting information from various sources as to what to expect.
Can you suggest a good resource or a simple explanation for each.
Can we link the various gases in the bulbs to the wavelengths seen?
Thank you

Hi,

Here are some references on LED light source spectra:

http://en.wikipedia.org/wiki/Light-emit ... _materials

http://www.opticsinfobase.org/view_arti ... q%3D0&org=

Here are resources on fluorescent lights

http://en.wikipedia.org/wiki/Fluorescen ... tted_light

This site has color spectrograph pictures with commentary on multiple lamp types and sources:
(You need to scroll down the page to see a link to emission spectra photos.)
http://ioannis.virtualcomposer2000.com/ ... html#1incp


Yes, you csn link the spectral lines you see from the bulbs to specific elements. The weblink just above does that for some of their spectra. You can find emission line wave lengths for many elements tabulated in the Handbook of Chemistry and Physics, which your school or public library will almost certainly have a copy of.

Your project sounds like it is off to a great start. I wish you great success in your science fair!

Best regards,

Barrett L. Tomlinson