What is radioactive decay used for?

Radioactive decay is the emission of radioactive particles namely alpha, beta and gamma. This decay property can be used in tracers like iodine-131 to trace the absorption of iodine by the thyroid gland. It can also be used in carbon dating to detect the age of materials. Another use is in paper manufacture, it's used to make sure the paper is of the desired thickness. There are many more you can search up!!