The study of spectra in all its forms plays an important role in determining the chemical make-up of matter. Spectra can be considered as the fingerprints of matter. Every atom emits its own characteristic spectrum of light. The study of spectra has been an important tool for scientists to identify the chemical composition of substances isolated in chemical, biological, and astronomical research. For example, the study of spectra from starlight showed that the sun and some of the stars are made of hydrogen and helium. Helium was actually discovered in the analysis of solar spectra before it was discovered on earth. In this activity we will learn how scientists were able to discover helium on the sun even though they had not yet isolated it on earth.

Warning: Never look directly at the sun. To view the sun’s spectrum place white paper in sunlight. Look at the light reflected from the paper.