Breadcrumb
7B11.15 - Spectral Lines/Spectroscopy - Sodium Absorption
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Code Number: 7B11.15
Demo Title: Spectral Lines/Spectroscopy - Sodium Absorption
Condition: Excellent
Principle: Spectra of Various Gases, Spectral Lines of Elements
Area of Study: Modern Physics, Optics, Astronomy
Equipment:
Slide Projector, Sodium Absorption Apparatus, (Variable Slit and Lens Unit, Fischer Burner Unit), Grill Lighter, Plexiglas Stand for Slide Projector, Diffusing Screen if desired, and Rock Salt.
Procedure:
See also: 7B11.15 in Astronomy.
The sodium absorption stuff is set up as shown. Observe the distances fairly carefully as it is a critical part of making this work. The lens of the slide projector will need to be turned almost clear out. Light the burners and wait until they burn with a bright yellow flame before putting into the light path. Focus the camera onto the red-yellow end of the spectrum showing on the grating.
Note: The burners must be lined up in the light path.
The white light spectrum observed will have many streaks in it due to light bulb configurations. To minimize this the use of a diffusing screen is advised. The one that we are using is in a 35 mm slide holder and can be inserted directly into the slide projector.
References:
- Colin S. Wallace, Edward E. Prather, Seth D. Hornstein, Jack O. Burns, Wayne M. Schlingman, and Timothy G. Chambers, "A New Lecture-Tutorial for Teaching about Molecular Excitations and Synchrotron Radiation", TPT, Vol. 54, #1, Jan. 2016, p. 40.
- Michael Gore, "Shedding Light on Darkness", TPT, Vol. 45, #4, Apr. 2007, p. 250.
- Paul Hewitt, "Figuring Physics: Absorption Spectra", TPT, Vol. 43, #2, Feb. 2005, p. 74.
- Bruce C. Palmquist, "Interactive Spectra Demonstration", TPT, Vol. 40, #3, Mar. 2002, p. 140.
- Donald F. Collins, "Video Spectroscopy - Emission, Absorption, and Flash", TPT, Vol. 38, #9, Dec. 2000, p. 561.
- Kenneth Brecher, "Do Atoms Really 'Emit' Absorption Lines?", TPT, Vol. 29, #7, Oct. 1991, p. 454.
- Haym Kruglak, "Apparatus for Displaying Three Types of Spectra", TPT, Vol. 23, #5, May 1985, p. 314.
- Zenon Gubanski, "Demonstrating the Line Absorption Spectrum of Sodium Vapor", TPT, Vol. 18, #2, Feb. 1980, p. 140.
- "Did Cave Men Ever See a Fraunhofer Spectrum", TPT, Vol. 15, #2, Feb. 1977, p. 93.
- Mary Jane Gary and Victor G. Mossotti, "Nonflame Absorption Spectroscopy: A Technique for Elemental Analysis", TPT, Vol. 13, #6, Sept. 1975, p. 362.
- Edwin Paul Heideman, "Absorption Spectra", TPT, Vol. 9, #6, Sept. 1971, p. 345.
- Robert de Levie, "On Deconvolving Spectra", AJP, Vol. 72, #7, July 2004, p. 910.
- Noojin Walker, Jr., "A Spectroscopic Sodium Flame", AJP, Vol. 31, #12, Dec. 1963, p. 945.
- Wallace A. Hilton, "S-5", Experiments in Optical Physics, p. 55 - 56.
- Wallace A. Hilton, "S-4", Experiments in Optical Physics, p. 53.
- George M. Hopkins, "Light", Experimental Science, p. 214 - 215.
- Isaac Asimov, "What Are Little Stars Made Of?", Fantasy and Science Fiction Magazine, p. 125 - 134.
- W. Bolton, "Sodium Impurity", Book 2 - Waves and Particles, Physics Experiments and Projects, 1968, p. 81 - 82.
- W. Bolton, "Beer's Law", Book 2 - Waves and Particles, Physics Experiments and Projects, 1968, p. 47 - 48.
- Joseph Frick, "#7 - Frauenhofer's Lines", Physical Technics: Or, Practical Instructions for Making Experiments in Physics and the Construction of Physical Apparatus with the Most Limited Means", p. 196.
Video Credit: Jonathan M. Sullivan-Wood.