According to Einstein’s theory of relativity, mass can be converted into energy and vice-versa. The lightest elementary particle, taken to be the electron, has a mass equivalent to 0.51 MeV of energy. According to Einstein's theory of relativity has a mass equivalent to 0.51 MeV of energy. mass can be converted into energy and vice-versa. The lightest elementary particle taken to be the electron October 16, 2020 Category: Uncategorised (JEE Advanced Physics by BM Sharma + GMP Solutions) , Facebook Messenger WhatsApp Share this:TwitterFacebook Related