sentence: Radioactive atoms have unstable nuclei.
sentences_after: Their nuclei are unstable because the arrangement of protons and neutrons in them are unsteady, making them shake until that they begin to decay and change into completely different types of atoms by releasing certain types of radioactive particles, such as alpha particles, beta particles or gamma rays, and possibly by fissioning into smaller nuclei. This is known as radioactive decay.
concept_name: radioactive atom
headings: Half-life (element)
categories: Nuclear physics