Question: how to calculate kinetic energy in electron volts?
Answer: Note that 1 eV is the kinetic energy acquired by an electron or a proton acted upon by a potential difference of 1 volt. The formula for energy in terms of charge and potential difference is E = QV. So 1 eV = (1.6 x 10^-19 coulombs)x(1 volt) = 1.6 x 10^-19 Joules.