Generally elements with atomic number more than 82 show radioactivity and disintegrated to small nuclei with the emission of alpha, beta, proton, neutron particles or gamma rays. This nuclei with decomposed is called as parent nuclei and the product nuclei is termed as daughter nuclei.
The atomic number and mass depends upon the type of radioactive rays emitted during nuclear reaction. The decay of radioactive parent nuclei to stable nuclei is known as radioactive decay or nuclear decay.
The type of decay depends on the type of radioactive particles emitted in decay. For example,
- Alpha decay
- Beta decay
- Gamma decay