A gamma ray photon creates an electron-positron pair. If the rest mass energy of an electron is 0.5MeV and the total K.E. of the electron-position pair is 0.78MeV, then the energy of the gamma ray photon must be. A gamma ray photon creates an electron-positron pair. If the rest mass energy of an electron is 0.5MeV and the total K.E. of the electron-position pair is 0.78MeV then the energy of the gamma ray photon must be. June 17, 2021 Category: Cengage NEET by C.P Singh , Chapter 14 - Nuclear Physics and Radioactivity , Part 2 , Facebook Messenger WhatsApp Share this:TwitterFacebook Related