The Lorentz oscillator model can account for the response of material bodies to electromagnetic waves. The model assumes that the electrons can be simulated as atomic oscillators. Thus an incoming monochromatic electromagnetic wave can cause the valence electrons to oscillate harmonically. This behavior of the material is characterized by the dielectric constant, which can be related to the refractive index and extinction coefficient. In this Demonstration, these optical properties of the material are related to the selected parameters of the atomic oscillators and plotted as functions of the radiation frequency.