Astronomy 110 Spectroscopy Lab

Unknown Element Identification Worksheet

Name: _______________________________________ Section: _____________

1) At one station of this lab is a small, grey free-standing spectroscope pointed at an unknown element. You are to estimate the wavelengths of the strongest emission lines as viewed in this spectroscope. Write them into the following table while noting the color of the emission line.

Observed Wavelength (nanometers)	Color of line

2) Compare your measured wavelengths with the list of emission lines of three elements listed below. Note that you may not be able to see each of the listed lines for each element, depending on the color sensitivity of you eyes, as well as the fact that some of the lines are much weaker than others. Most humans cannot see light with wavelengths shorter than 400 nm, or longer than 700 nm. Which element is the unknown element? ________________________________.

Hydrogen	Helium	Argon
656.3	728.1	714.7
486.1	667.8	687.1
434.0	587.5	675.2
410.2	501.5	560.6
397.0	492.1	557.2
388.9	471.3	549.5