Experiment 14: Color and Spectra

Introduction: The purpose of this experiment is to measure the wavelengths of the various colors in the light spectra as well as observe the colors emitted by single elements using a diffraction grating.

White Light Procedure: We placed a light source on a table and attached a diffraction grating to a 2 meter stick touching the light source. We then put another meter stick perpendicular the first touching the light source

We then looked through the diffraction grating and observed the entire light spectrum and marked where the various colors began and ended.

Data and Analysis: The diagram and formula below was used to find the wavelengths expressed in visible light

The work for finding the wavelength and the uncertainty associated is below. The actual value is also compared. Our data is supported fairly well.

Single Element Procedure: 

The set up is the same as with the white light source except the light source was replaced with a hydrogen gas tube.

The tube was looked at through the diffraction grating and only three lines were visible. There are actually 4 but only 3 can be seen.

Data and Analysis: We used marked the meter stick where the lines were and used the same formula to calculate the wavelength with uncertainty for the three lines.

The actual wavelengths visible for hydrogen are 410, 434, 468, and 656 nm. only the 434 nm is within uncertainty. This is probably due to the fact that the meter sticks were not exactly touching the hydrogen tube and the diffraction grating was a cheap plastic one.