Physics307L:People/Martin/Notebook/070912
Balmer Series
see comment
Adjusting the Spectrometer
This took us a while to figure out how to do. Take a known light seen and wavelength pair. Align the dial to the specified wavelength, now adjust the spectrometer. To adjust the spectrometer you must first remove the prism cover. Loosen the prism's clamp and rotate the prism till the specified color of light falls into the cross hair. Now the measurement that you get for this specific color will be correct. Tighten the clamp and replace the cover.
Materials and set up
Spectrometer (Last years manual has a diagram), a spectrum tube power supply SP200 at 5000 volts, and three various spectrum tubes of Hydrogen Deuterium, and Mercury. We set up the power supply with the correct spectrum tube in front of the spectrometer and turned it on looking through the eyepiece to see the spectrum lines incident from the light. During our initial set up of the experiment we discovered that different results were obtained by approaching the spectral lines from the right then from the left. We decided to fix this problem by taking measurements both from the left and from the right.
Mercury
Our Measurements
red clockwise- 695 nm, 695 nm, 697 nm, 696 nm, 696.5 nm,
red counterclockwise- 700 nm, 696 nm, 702 nm, 701 nm, 702 nm
yellow 1 clockwise- 576.5 nm, 579 nm, 577.75 nm, 578 nm, 578 nm
yellow 1 counterclockwise- 579.5 nm, 580 nm, 580.5 nm, 581 nm, 580.5 nm
yellow 2 clockwise- 574.5 nm, 574 nm, 576 nm, 576 nm, 575.5 nm
yellow 2 counterclockwise- 576.75 nm, 576 nm, 578 nm, 577.5 nm, 577.25 nm
green clockwise- 544 nm, 544.5 nm, 545 nm, 545.75 nm, 545.25 nm
green counterclockwise- 545.4 nm, 546.1 nm, 547.5 nm, 546.85 nm, 547 nm
violet clockwise- 435 nm, 435.4 nm, 435.25 nm, 435.9 nm, 435.4 nm
violet counterclockwise- 435.75 nm, 435.6 nm, 435.9 nm, 436.2 nm, 436.1 nm
The True Results
red- 690.75 nm
yellow 1- 579 nm
yellow 2- 577 nm
green- 546.1 nm
violet- 435.8 nm
see comment
The Hydrogen Light
Our Measurements
red light clockwise rotation- 656.5 nm, 656 nm, 656 nm, 656 nm, 655.5 nm (n=3)
red light counterclockwise rotation- 656 nm, 660 nm, 659 nm, 659.5 nm, 658.5 nm (n=3)
blue light clockwise rotation- 485.5 nm, 485.5 nm, 485.25 nm, 485.5 nm, 485.1 nm (n=4)
blue light counterclockwise rotation- 486.5 nm, 486.2 nm, 486.5 nm, 486.25 nm, 486.75 nm (n=4)
violet light clockwise rotation- 433.5 nm, 434.1 nm, 433.6 nm, 433.6 nm, 433.7 nm (n=5)
violet light counterclockwise rotation- 434.1 nm, 434.1 nm, 434.25 nm, 434.25 nm, 434.3 nm (n=5)
violet #2 light clockwise rotation- 410 nm, 410.5 nm, 410.1 nm, 409.8 nm, 409.6 nm (n=6)
violet #2 light counterclockwise rotation- 410.25 nm, 410.25 nm, 410.25 nm, 410.2 nm, 410.1 nm (n=6)
The True Results
red- 656.3 nm
blue- 486.1 nm
violet- 434.1 nm
violet 2- 410.2 nm
value for R - 10,978,682 m−1 +/- 6000 m−1 the real value for the rydberg constant is 10,973,735.3 m−1 which falls into the std dev. the mean has a .45 percent error from the true value.
The Deuterium Light
Our measurements
red light clockwise rotation- 655.2 nm, 654 nm, 656 nm, 654.5 nm, 655.75 nm
red light counterclockwise rotation- 657.5 nm, 658 nm, 658.5 nm, 659.5 nm, 659 nm
blue-green light clockwise rotation- 484.9 nm, 486 nm, 485 nm, 484.9 nm, 485.1 nm
blue-green light counterclockwise rotation- 486.1 nm, 485.5 nm, 486.1 nm, 486.2 nm, 486.1 nm
violet light clockwise rotation- 434.6 nm, 434.3 nm, 433.6 nm, 433.9 nm, 433.5 nm
violet light counterclockwise rotation- 434.1 nm, 433.95 nm, 434 nm, 434.2 nm, 434.2 nm
violet #2 light clockwise rotation- 409.5 nm, 411 nm, 409.3 nm, 409.6 nm, 409.3 nm
violet #2 light counterclockwise rotation- 410 nm, 409.5 nm, 410 nm, 410.2 nm, 410.1 nm
note violet #2 was really faint and hard to see. The measurements on this color were hard to take and there might be some error in that.
we got 10983540 m-1 +/- 11080.27 m-1 for the rydberg constant for deuterium. this seems right because the rydberg constant for deuterium should not be much different then that of hydrogen.
The Na yellow lines
we could not find the sodium tube.