This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: Eric Chong PHYS C1493 Partner: Albert Lee Lab Date: November 2, 2006 Experiment 7: The Spectrum of the Hydrogen Atom Introduction In this experiment we observe inherent characteristics of a light source as a discrete light spectrum which consists of sharp monochromatic lines, where by use of a collimator tube, diffraction grating, and an eyepiece attached to a rotating table (accurate to minutes of a degree), we can measure the wavelengths of the various colors of the light spectrum and thus their respective initial orders. Our experiment dealt exclusively with the emission of bright light that occurs from the dielectric breakdown of hydrogen. We can relate the various angles at which we visualize each of the colors in the spectrum to the wavelength λ and the initial order n i : 2 1 1 1 4 i R n λ = , sin d m θ λ = , where the initial order n i is an integer corresponding to the various colors of light, R is the Rydberg constant with value R = 1.0974 x 10 7 m1 , and d is the grating lattice constant corresponding to the diffraction grating used. Procedure By observation of the equations given above, we can see that initially we would need to find the wavelength of the various colors of light, and in order to do so, require the value of the grating lattice constant d . They are related by the 2 nd equation, sin d m θ λ = . Thus the first procedure required the calibration of the eyepiece with its related equipment, being sure that the rotating table had been set to a central value, in this case 180 ± 1/60°, so that all angles recorded could be calculated relative to this central value. Also, the equipment should be set up such that no outside light interfered with the observation of solely the lamp. After calibration, we begin observation of first the helium lamp under the eyepiece, because we are already given the wavelength for this source of light. The collimator tube takes the light from the helium lamp and makes the light rays from it parallel – a necessary step that allows proper viewing of the light spectrum. We observe the first yellow light that occurs to the left and the right of the central position, and record these angles. Taking the average of these relative angles of light in the first order (or m = 1 ), we can plug this into the equation to find our grating constant d . Now that we have obtained our d , we can use this to find the wavelengths of colors of...
View
Full
Document
This note was uploaded on 12/16/2010 for the course PHYS 1493 taught by Professor Lab during the Spring '08 term at Columbia.
 Spring '08
 LAB
 Physics, Light

Click to edit the document details