Some processes by which nuclei decay emit subatomic particles with unique properties.
An alpha particle, or helium nucleus, consists of two neutrons and two protons, and is symbolized by α or He2+
Neutrinos and antineutrinos are subatomic particles with no electrical charge, have negligible mass, and are symbolized by and , respectively.
Neutrinos and antineutrinos only interact with matter via the weak force and the gravitational force, which results in very little interaction with normal matter.
Positrons, or antielectrons, are subatomic particles with an electric charge opposite of an electron, have the same mass as an electron, and are symbolized by e+or + .
Nuclei can undergo radioactive decay via alpha decay, beta-minus decay (β− ) , beta-plus decay (β+ ) , and gamma decay ( ) .
In all nuclear decays, nucleon number (the number of neutrons and protons), lepton number (the number of electrons and neutrinos), and charge are conserved.
Alpha decay occurs when a nucleus ejects an alpha particle.
Beta-minus decay occurs when a neutron changes to a proton by emitting an electron and antineutrino.
Beta-plus decay occurs when a proton changes to a neutron by emitting a positron and neutrino.
Gamma decay occurs after a nucleus has undergone alpha or beta decay, and an excited nucleus decays to a lower energy state by emitting a photon.
The type of decay exhibited by a given nucleus is determined by the isotope of the element