Maths, Physics Revision Physicss Maths Physics Physics A Level Physics Home Maths Maths Revision hut Photo electric effect When photons of Electromagnetic Radiation fall onto the surface of metal the energy of one  photon is given  up to one electron in the metal -13.6eV - 3.4eV - 1.5eV - 0.85eV - 0.54eV You can use the wave equation to work out the wavelength of this Radiation  Speed =  wavelength x frequency  (speed = 3x 108 m/s)  Wavelength = speed/ frequency 3 x 108 / 2.9 x 1015  = 9.7 x 10-8m