51猎奇入口

Concepts

Atomic spectra

Overview

A spectrometer camera observes the spectrum of a tea light as baking soda is added to it. The sodium doublet shows up prominently in the resulting spectrum.

Details

Equipment

• [2] Tea light
• [1] Barbeque lighter or matches
• [1] Spectrometer camera with tripod
• [1] Box of baking soda
• [1] Scoop or wet wipes
• [1] Pair of black panels with stand
• [1] Lab jack
• [1] Computer with RSpec software
• [1] Extension cord (if necessary) 

Classroom Assembly

1. Place the spectrometer camera and plug it into the computer.
2. Place the tea lights on the lab jack and adjust the lights to the height of the spectrometer camera.
3. Light the tea lights.
4. Place the black panels so that everything in the camera's view to the right of the tea lights is blocked by the panels.
5. In the RSpec software, adjust the spectrum measurement area to be somewhere in the middle of the live view.
6. Blow out the tea lights.

Important Notes

• The spectrometer works best in darkness, though the black panels help if turning off most of the lights is impractical.
• The black panels should block everything on the camera's right-side field of view.
• Practice with the RSpec software required.

Script

1. Turn off or dim as many lights as possible.
2. Light the tea lights. Observe the resulting spectrum in the camera software.
3. Add a bit of baking soda to the tea light being measured. Note the increasing intensity of the yellow part of the spectrum.
4. Click on the vertical lines icon to bring up the elements window. Check off sodium to show the reference wavelengths on the graph.
5. Switch to observing the other tea light (with no baking soda). Note the other tea light has significantly more yellow.
6. Blow out both tea lights.

Additional Resources