Physics307L:People/Carrillo/Electron Diffraction

Balmer Series Lab Summary

• Please note that Ginny was my lab partner for this lab.

Purpose

The purpose of this lab was to verify the de Broglie hypothesis and to measure the spacing of planes in graphite. To do this, we used en electron diffraction tube, a wavetek digital multimeter, calipers, and a 3B DC power supply (Model U3310).

To view the procedure, setup and calculations please click on the link below.

Calculations and Analysis

• As you can see from my lab notebook, the calculated inner and outer diameters and percent errors are listed below

• [math]\displaystyle{ d_{inner} = 0.19524 +/- 0.001 nm\,\! }[/math]

[math]\displaystyle{ d_{outer} = 0.11153 +/- 0.0006 nm\,\! }[/math]

• [math]\displaystyle{ \% error=\frac{d_{inner}-d_{measured}}{d_{inner}}\,\! }[/math]

[math]\displaystyle{ \% error_{inner} = 8.34 %\,\! }[/math]

[math]\displaystyle{ \% error_{outer} = 9.33 %\,\! }[/math]

Conclusion

As you can see from our results, the error for the inner diameter's lattice spacing was lower than the outer diameter's spacing, although the standard error of the mean for the inner diameter's lattice spacing was larger than that of the outer diameter. Our error must have come from the fact that the outer diameter became fuzzier as we lowered the voltage.