A thin beam of white light is directed at a flat sheet of silicate flint glass at an angle of 20.0 to the surface of the sheet.

A thin beam of white light is directed at a flat sheet of silicate flint glass at an angle of 20.0 to the surface of the sheet. Due to dispersion in the glass, the beam is spread out as shown in a spectrum . The refractive index of silicate flint glass versus wavelength is graphed in Fig. 33.18 in the textbook.