All large radioactive atoms decay into smaller atoms by releasing alpha particles. Each alpha particle has 2 protons, 2 neutrons, and 0 electrons. The table below describes several neutral, low-mass atoms. An alpha particle is also referred to as a nucleus of which isotope?

All large radioactive atoms decay into smaller atoms by emitting alpha particles which consists of two protons and two neutrons. An alpha particle can also be thought of as the nucleus of a helium atom and as such they are sometimes referred to as He2 +. The positive charge is due to the lack of two electrons.