Radioisotopes used for dating
(Recall that tritium, H, is a radioactive isotope of hydrogen.) Tracers can also be used to follow the steps of a complex chemical reaction.
After incorporating radioactive atoms into reactant molecules, scientists can track where the atoms go by following their radioactivity.
Radioactivity was discovered in 1896 by French physicist Henri Becquerel.
By 1907 study of the decay products of uranium (lead and intermediate radioactive elements that decay to lead) demonstrated to B. Boltwood that the lead/uranium ratio in uranium minerals increased with geologic age and might provide a geological dating tool.
The principal evidence for the antiquity of Earth and its cosmic surroundings is: Spontaneous breakdown or decay of atomic nuclei, termed radioactive decay, is the basis for all radiometric dating methods.
Radioactive isotopes are useful for establishing the ages of various objects.
The half-life of radioactive isotopes is unaffected by any environmental factors, so the isotope acts like an internal clock.
This exposure kills a lot of the bacteria that cause spoilage, so the produce stays fresh longer.
Eggs and some meat, such as beef, pork, and poultry, can also be irradiated.