How Do You Calculate The Energy Needed To Remove An Electron?

How Do You Calculate The Energy Needed To Remove An Electron? 1) Calculate the electron’s kinetic energy using E(k) = 1/2 mv^2. This is the ‘excess’ energy. 2) electron’s kinetic energy + sodium’s work function (per atom) = energy of incoming photon. How do you calculate the wavelength needed to remove an electron? If a