User:Randy Jay Lafler/Notebook/Physics 307L/Balmer Series Summary

Purpose/Procedure

The purpose for the Balmer Series lab is to determine the Rydberg constant for hydrogen and compare it to the Rydberg constant for deuterium. We first calibrated the spectrometer with a mercury lab and a table of the known spectral line wavelengths. After that we used the spectrometer to measure the wavelengths of the spectral lines for hydrogen and deuterium. We then adjusted our raw measurements by the calibration and plotted our data so that the slope of the plot is the Rydberg constant.

Data Overview

The two Rydberg constants we determined are

[math]\displaystyle{ R_H=1.10(4)*10^7/m\! }[/math]

[math]\displaystyle{ R_D=1.104(5)*10^7/m\! }[/math]

Error

The accepted value for the Rydberg constant for hydrogen is 1.0974*10^7/m. The accepted value is within one standard error of our data, and the best answer we obtained is very close to the accepted value. Therefore, I believe that we did good measurements. At first, we had a hard time seeing the spectral lines for the hydrogen, and we chose the lines that were the sharpest and brightest. This is why we calculated a wavelength for a yellow spectral line for the hydrogen even though there is not one. Also, we adjusted the last measurement in calibration factors from -9 to 2nm to match the rest of our calibration measurements. We did this because the jump to negative values did not make sense and because it made our measurements for the Rydberg constant more consistent. More explanation is given in my notebook.

Acknowledgements

Emran was my lab partner again.