Scientists can use the half-life of Carbon-14 to determine the approximate age of organic objects less than 40,000 years old.
By determining how much of the carbon-14 has transmutated, scientist can calculate and estimate the age of a substance. Isotopes with longer half-lives such as Uranium-238 can be used to date even older objects.
It is important to recognize that the intensity or amount of radiation is decreasing due to age but not the penetrating energy of the radiation.
The atoms that are involved in radioactive decay are called isotopes.
In reality, every atom is an isotope of one element or another.
The rate at which a radioactive isotope decays is measured in half-life.
The term half-life is defined as the time it takes for one-half of the atoms of a radioactive material to disintegrate.
In the field of nondestructive testing radiographers (people who produce radiographs to inspect objects) also use half-life information.
A radiographer who works with radioisotopes needs to know the specific half-life to properly determine how much radiation the source in the camera is producing so that the film can be exposed properly.
Half-lives for various radioisotopes can range from a few microseconds to billions of years.
See the table below for a list of radioisotopes and each of unique their half-lives. After 86 minutes, half of the atoms in the sample would have decayed into another element, Lanthanum-139.
If they can begin to comprehend that it is random and spontaneous, they end up feeling less nervous about the whole thing.