User:Emran M. Qassem/Notebook/Physics 307L/2010/11/15: Difference between revisions

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==Balmer Series==
=Balmer Series=
===Purpose===
==Purpose==
* To determine the Rydberg constant by measuring the wavelengths of the spectrum of Hydrogen and Deuterium in the Balmer series.
* To determine the Rydberg constant by measuring the wavelengths of the spectrum of Hydrogen and Deuterium in the Balmer series.
* This can be done using Balmers equation and relating the wavelengths to the principle quantum number of the initial state.
* This can be done using Balmers equation and relating the wavelengths to the principle quantum number of the initial state.


===Equipment===
==Equipment==
[[Image:BalmerSpectrometer.jpg|thumb|right|Spectrometer]]
[[Image:BalmerSpectrometer.jpg|thumb|right|Spectrometer]]
[[Image:BalmerCrystal.jpg|thumb|right|Crystal]]
[[Image:BalmerCrystal.jpg|thumb|right|Crystal]]
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* Mercury, Hydrogen and Deuterium tubes
* Mercury, Hydrogen and Deuterium tubes


===Safety===
==Safety==
* High voltage on power supply, possibility of shock.
* High voltage on power supply, possibility of shock.
* Sensitive crystal, do not drop or over tighten clamp.
* Sensitive crystal, do not drop or over tighten clamp.
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* Spectrometer is very old and precise equipment, do not force or jam things.
* Spectrometer is very old and precise equipment, do not force or jam things.


===Setup===
==Setup==
From [http://www-hep.phys.unm.edu/~gold/phys307L/manual.pdf Professor Gold's Manual]:
From [http://www-hep.phys.unm.edu/~gold/phys307L/manual.pdf Professor Gold's Manual]:
* Before turning out the lights or mounting the bulb, focus the cross-hairs by pulling the eyepiece in and out.
* Before turning out the lights or mounting the bulb, focus the cross-hairs by pulling the eyepiece in and out.
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* Adjust the slit width so that it appears to be a thin line with enough intensity to see it well.
* Adjust the slit width so that it appears to be a thin line with enough intensity to see it well.


===Procedure===
==Procedure==
* Calibration
* Calibration
** Based on the color you see, use the table of wavelengths to find out what wavelength you are looking at.
** Based on the color you see, use the table of wavelengths to find out what wavelength you are looking at.
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** Look up the principle quantum numbers for Hydrogen (balmer series image works).
** Look up the principle quantum numbers for Hydrogen (balmer series image works).
** Use this data with the Balmer equation to calculate R.
** Use this data with the Balmer equation to calculate R.
 
<br style="clear:both;"/>
===Data===
==Data==
[http://openwetware.org/images/e/ea/Balmer.xls Balmer Series XL Doc]
[http://openwetware.org/images/e/ea/Balmer.xls Balmer Series XL Doc]


[[Image:BalmerRawData.jpg|width=400]]
[[Image:BalmerRawData.jpg|700px]]
[[Image:BalmerHydrogen.jpg|width=400|height=500]]
[[Image:BalmerHydrogen.jpg|500px]]
[[Image:BalmerDeuterium.jpg|width=400|height=500]]
[[Image:BalmerDeuterium.jpg|500px]]
 


===Calculations===
==Calculations==
===Error===
==Error==
===Acknowledgments/citations===
==Acknowledgments/citations==




Revision as of 15:03, 21 December 2010

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Balmer Series

Purpose

  • To determine the Rydberg constant by measuring the wavelengths of the spectrum of Hydrogen and Deuterium in the Balmer series.
  • This can be done using Balmers equation and relating the wavelengths to the principle quantum number of the initial state.

Equipment

Spectrometer
Crystal
Wavelength Positioner
Bulb
Deuterium Spectrum
  • Constant Deviation Spectrometer
  • Spectrum Tube Power Supply Model SP200, 5000 volts, 10MA.
  • Mercury, Hydrogen and Deuterium tubes

Safety

  • High voltage on power supply, possibility of shock.
  • Sensitive crystal, do not drop or over tighten clamp.
  • Bulbs are fragile, be careful not to drop.
  • Bulbs get hot, be careful when handling so as not to burn yourself.
  • Spectrometer is very old and precise equipment, do not force or jam things.

Setup

From Professor Gold's Manual:

  • Before turning out the lights or mounting the bulb, focus the cross-hairs by pulling the eyepiece in and out.
  • Mount the mercury bulb and turn it on, being careful not to shock yourself.
  • Open the slit width to a wide opening and place the bulb close to the slit, approximately 1 cm or less away.
  • Change the wavelength positioner (rotates the crystal) until you can see a spectrum line.
  • Look through the eyepiece and turn the knurled nob to focus the slit.
  • Adjust the slit width so that it appears to be a thin line with enough intensity to see it well.

Procedure

  • Calibration
    • Based on the color you see, use the table of wavelengths to find out what wavelength you are looking at.
    • Set the wavelength positioner to that wavelength.
    • Turn the crystal manually so that the line appears in the cross-hairs and coincides with the wavelength positioner value.
    • Find each spectrum line and write down the actual value and the measured value and record the difference so that you have a calibration.
  • Actual experiment
    • Now mount Hydrogen and Deuterium and measure all of their spectral lines and record their wavelengths.
    • Look up the principle quantum numbers for Hydrogen (balmer series image works).
    • Use this data with the Balmer equation to calculate R.


Data

Balmer Series XL Doc

Calculations

Error

Acknowledgments/citations


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