This has to do with figuring out the age of ancient things.If you could watch a single atom of a radioactive isotope, U-238, for example, you wouldn’t be able to predict when that particular atom might decay.
Many isotopes have been studied, probing a wide range of time scales.C and counting the amount of each) allows one to date the death of the once-living things.For example, in 1991, two hikers discovered a mummified man, preserved for centuries in the ice on an alpine mountain.Later called Ötzi the Iceman, small samples from his body were carbon dated by scientists.Nuclear reactions provide us with enormous amounts of energy.
Radioactive isotopes are used to determine the age of old artifacts, diagnose disease, and treat certain types of medical conditions.It might take a millisecond, or it might take a century. But if you have a large enough sample, a pattern begins to emerge.It takes a certain amount of time for half the atoms in a sample to decay. Radiocarbon decays slowly in a living organism, and the amount lost is continually replenished as long as the organism takes in air or food.Once the organism dies, however, it ceases to absorb carbon-14, so that the amount of the radiocarbon in its tissues steadily decreases.There's a small amount of radioactive carbon-14 in all living organisms.