In this article, we will learn about the mass of an electron in kg, grams, amu and eV. We will also learn the rest mass of an electron along with some FAQs The electron rest mass (symbol: me) is the mass of a stationary electron , also known as the invariant mass of the electron . It is one of the fundamental constants of physics. It has a value of about 9.109×10−31 kilograms or about 5.486×10−4 daltons, equivalent to an energy of about 8.187×10−14 joules or about 0.5110 MeV. The mass of electron is the mass of a stationary electron described by the equation me = 9.10938356 × 10-31 kilograms where me is the rest mass of electron . Therefore, electrically neutral atoms/molecules must have an equal number of electrons and protons. Although the magnitude of the charges held by protons and electrons are the same, the size and mass of an electron are much smaller than that of a proton (the mass of an electron is roughly 1/1837 the mass of a proton).
