Did you know that Helium was discovered on the Sun before it was discovered on earth? Astronomers found extra lines in the spectrum of the sun which they guessed was an undiscovered element. You will be shown the spectra of two combined elements again, only this time...we might have hidden some of the samples you can choose from. It may or may not be possible to create the spectra with the elements at hand. If you find one that matches...but can't find another...then select "The sample is not known" from the pulldown.
