Use Planck"s constant (h = 6.6260755 x 10-34 J-s) to determine the Energy or frequency for electromagnetic waves: E = h. Describe the photoelectric effect. Calculate the wavelength and/or frequency of the photon of light needed to cause an electron to be emitted from a material. Compare and contrast continuous spectrum and line spectrum as they relate to the elements. Describe how spectral lines can be used to identify elements.