are classified by its frequency or wavelength, but only a few teachers know how a spectrometer really works, and how we can measure the wavelength of each color. Nowadays it is relatively easy to produce a spectroscope and watch the light spectrum of sunlight (the rainbow colors) or of artificial light. There are lots of optical prisms and recycled materials like CDs and DVDs, or diffraction gratings in the market, at a low cost price that can disperse the white light into its components. However, spectrometers are usually expensive, and schools are reluctant to spend a significant