These are called radioactive tracers, and they act like little atom labels or flags.
If they are being traced in locations where they shouldn't be, a more accurate diagnosis can be made.
The sun is essentially a fusion reactor creating energy by fusing hydrogen atoms together to form helium, and the sun is our primary source of energy.
The more carbon-14 that an artifact has, the more recent it is.The type of nuclear power that is most common on Earth is nuclear fission.Nuclear fission occurs when a heavier atom splits into smaller pieces.This makes the already slightly unstable heavy atom even more unstable, which causes it to split into smaller atoms and possibly eject a few neutrons.This releases a lot of energy because the original atom was so unstable.
Radioactive isotopes are used to determine the age of old artifacts, diagnose disease, and treat certain types of medical conditions.