Radioactive dating quiz
Because each nuclide has a specific number of nucleons, a particular balance of repulsion and attraction, and its own degree of stability, the half-lives of radioactive nuclides vary widely.For example: the half-life of The “m” in Tc-99m stands for “metastable,” indicating that this is an unstable, high-energy state of Tc-99.As long as an organism is alive, the amount of C-14 in its cellular structure remains constant.But when the organism dies, the amount of C-14 begins to decrease.We are told that these methods are accurate to a few percent, and that there are many different methods.
A useful application of half-lives is radioactive dating.
Carbon-14 (C-14), a radioactive isotope of carbon, is produced in the upper atmosphere by cosmic radiation.
The primary carbon-containing compound in the atmosphere is carbon dioxide, and a very small amount of carbon dioxide contains C-14.
This gives us the impression that all but a small percentage of the dates computed by radiometric methods agree with the assumed ages of the rocks in which they are found, and that all of these various methods almost always give ages that agree with each other to within a few percentage points.
Since there doesn't seem to be any systematic error that could cause so many methods to agree with each other so often, it seems that there is no other rational conclusion than to accept these dates as accurate.
It can’t be used to determine the age of a moon rock or a meteorite.