Radioactive decay is a spontaneous and random process ... If a sample of a tree (for example) contains 64 grams (g) of radioactive carbon after 5,730 years it will contain 32 g, after another ...

and the time it takes for one-half of a particular isotope to decay is its radioactive half-life. For example, about 1.5 percent of a quantity of Uranium 238 will decay to lead every 100 million ...

A spontaneous process means that it is not possible to say which particular nucleus will decay ... half-life of radioactive carbon-14 is 5,730 years. If a sample of a tree (for example) contains ...