Elements that have different number of neutrons in their nucleus are called Isotopes. This means that their mass number will also differ. Radioactive isotopes are the isotopes that have unstable nuclei which keep on dividing constantly with time. Due to this, constant breakdown of nuclei occur by the emission of radiations.
Radioactive isotopes have great implications in the field of science:
1. Isotopes of carbon are used to determine the age of rocks and fossils that are millions of years old. The process is called carbon dating.
2. Isotopes of some elements are used as biotechnology tools. They are used as tracers to trace the movement of certain drugs into human body. Also, they are used in identifying the sequence of DNA by the incorporation of radiolabeled probes.