The purpose should be several well structured sentences state both conceptual concepts and experimental techniques covered in this experiment. The procedure section should reference the lab manual and note any changes that were made in the procedure during experimentation.

The data section for this report should have the two data tables. The first table should have your helium calibration data. This should include a) the known He wavelengths and b) the experimental wavelengths you observed. The second data table is for your unknown data. This should include the following a) the unknown light source , b) observed values from the unknown light source, c) the corresponding colors, d) the corrected wavelength and e) the identity of your unknowns (Compare your corrected wavelengths to those shown in the reference spectra given in the background section).

The helium calibration, the unknown light source, observed values and corresponding colors are all data that can just be copied from your lab notebook. The corrected wavelength for the unknown can be determined from the helium calibration graph. To determine the corrected wavelength find each observed value on the x-axis of the calibration graph, now draw a line on your graph from that point up to your calibration line, next at the point where your new line and the calibration line intersect draw a line across to the y-axis. The value at that point on the y-axis is the corrected wavelength.

The calculation section should include the calibration graph for the helium data. This graph should have the experimental value for helium on the x-axis and the known helium wavelength on the y-axis. All graphing guidelines apply.

The conclusion section should be several well developed paragraphs which include the identity of each unknown light source. Along with the identity, a detailed explanation of how the identity of each light source was determined should be included. Lastly a discussion on possible errors should be included.

Answer the Following Questions:

1. What is the difference between an emission and absorption spectrum?


2. Each element has a unique set of wavelengths associated with it, how are these different wavelengths generated?


3. How does NASA use spectroscopy to explore far away planets?


4. We say that the Sun is a yellow star. What does this really mean?