5/15 Color and Spectra

Purpose
The purpose of this experiment is to determine a calibration graph of wavelength using the white light, determine the experimental wavelengths of the four hydrogen lines through a diffration grating, compare the theoretical wavelengths of the four hydrogen lines to the calibrated wavelengths for hydrogen atom.

Experiment

Set up: white light source

 

Set up: white light source

Set up: white light source

Spectra observed through a diffraction grating

derivation of λ = Dd/√(L²+D²)

 

measurements and calculation of wavelengths

a calibration function was determined.

spectra of a hygrogen gas

 

spectra of a hydrogen gas

 

calculating experimental wavelengths

 

calibrated wavelengths vs. theoretical wavelengths

 

 

Experimental calibrated wavelength (nm)	Theoretical wavelength (nm)
423±25	410
490±14	486
680±27	656

 

Conclusion

The four hydrogen lines are red, green, blue, and purple. In our experiment, red, green, and purple are observed. The blue light is not observed because the purple and teal light next to the blue are really light, so we did not see the blue. Ohter than the blue light, all the other three colors are observed, and the experimental wavelengths determined (calibrated) lies within the uncertainty range of the theoretical walengths calculated from the Rydberg equation for the hydrogen atom.