Mass deficiency describes the fact that the nuclei made up of protons and neutrons have a smaller The mass of a particle at rest. According to the theory of r... than the sum of the rest masses of the protons and neutrons forming the Positively charged nucleus of an atom. Its diameter amounts .... The mass difference is equal to the released The energy required to separate particles which are bound by.... For the Positively charged particle emitted by various radioactive m... with a mass of 4.00151 atomic mass units, the structure of two protons (1.00728 atomic mass units each) and two neutrons (1.00866 atomic mass units each), a mass defect of 0.03037 atomic mass units results. This corresponds to an Ability to do work or diffuse heat. The unit of energy is th... (The energy required to separate particles which are bound by...) of about 28 Megaelectron volt, 1,000,000 eV..