+Table II. Helium Emission Spectrum Line Number** Observed Experimental Experimental Color Wavelength, a Wavelength, Theoretical Wavelength, Percent Error (cm) (nm) (nm) (%) 1 violet 4.49 x 10-5 449 2 blue 4.71 x 10-5 471 3 green 5.01 x 10-5 501 4 yellow 5.91 x 10-5 591 15 orange 6.55 x 10-5 655 6 red 6.71 x 10-5 671 7 8 **You may not see all 8 lines.