is alpha emission the same as alpha decay
Alpha decay or α-decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle (helium nucleus) and thereby transforms or 'decays' into an atom with a mass number that is reduced by four and an atomic number that is reduced by two. An alpha particle is identical to the nucleus of a helium-4 atom, which consists of two protons and two neutrons. It has a charge of +2e and a mass of 4u. For example, uranium-238 decays to form thorium-234. Alpha particles have a charge +2, but as a nuclear equation describes a nuclear reaction without considering the electrons -- a convention that does not imply that the nuclei necessarily occur in neutral atoms -- the charge is not usually shown.
Alpha decay