Experiment 15: Color and Spectra

Objective:

To determine the wavelengths of visible light generated by white light and hydrogen atoms.

Equipment:

-Diffraction grating

-Light source

-Hydrogen gas tube

-1m stick

-2m stick

Procedure:

We set up the system as indicated in the lab manual:

Part I:

Part II:

We observed the diffracted distance and used this to calculate the wavelength using the formula provided in the lab manual.

Data/Calculations:

Derivation of formula used to calculate wavelength:

Part I white light:

We calculated the wavelengths of the longest (red) and shortest (violet) light and compared them with experimental values.

Our theoretical values:

Experimental values:

Comparison:

Part II Hydrogen Spectrum:

Conclusion:

We calculated very precise values using a diffraction grating, which means they are excellent for calculations involving unknown wavelengths emitted from elements in excited states.