The first day you eat half the pie, and save the other half for later.
The second day you eat half of what's left (leaving 1/4 of the original pie).
This radioactivity can be used for dating, since a radioactive 'parent' element decays into a stable 'daughter' element at a constant rate.The rate of decay (given the symbol λ) is the fraction of the 'parent' atoms that decay in unit time.For geological purposes, this is taken as one year.The good news is that the decay rate from parent element to daughter element is constant (we assume), and is called the "half-life" (clever name, huh? So, when geologist find one of the unstable elements in a rock, all they have to do is measure how much of the parent element remains, how much of the daughter element has been formed, apply the half-life value, and do the math. Radioactive dating is a method of dating rocks and minerals using radioactive isotopes.
This method is useful for igneous and metamorphic rocks, which cannot be dated by the stratigraphic correlation method used for sedimentary rocks. Some do not change with time and form stable isotopes (i.e.
those that form during chemical reactions without breaking down).
The unstable or more commonly known radioactive isotopes break down by radioactive decay into other isotopes.
Radioactive decay is a natural process and comes from the atomic nucleus becoming unstable and releasing bits and pieces.
These are released as radioactive particles (there are many types).
This decay process leads to a more balanced nucleus and when the number of protons and neutrons balance, the atom becomes stable.