What causes a nucleus to become radioactive
Return to questions. 1) A positively charged particle made up of two protons and two neutrons and released by a radioactive nucleus is the alpha particle. 2) An electron released by a radioactive nucleus that causes a neutron to change into a proton is called a beta particle.3) The amount of time for half the atoms in a radioactive sample to decay is called the half-life.eturn to questions. 1) A positively charged particle made up of two protons and two neutrons and released by a radioactive nucleus is the alpha particle. 2) An electron released by a radioactive nucleus that causes a neutron to change into a proton is called a beta particle.