Radioactive decay and carbon dating
Radiocarbon dating (usually referred to simply as carbon-14 dating) is a radiometric dating method.
It uses the naturally occurring radioisotope carbon-14 (14C) to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years old.
Radiocarbon dating can be used on samples of bone, cloth, wood and plant fibers.
The half-life of a radioactive isotope describes the amount of time that it takes half of the isotope in a sample to decay.
It has been determined that the rate of radioactive decay is first order.
We can apply our knowledge of first order kinetics to radioactive decay to determine rate constants, original and remaining amounts of radioisotopes, half-lives of the radioisotopes, and apply this knowledge to the dating of archeological artifacts through a process known as carbon-14 dating.
Plants take in carbon-14 through the process of photosynthesis.Scientists now know that most elements come in more than one version. When the dry periods ended and the water level rose, the trees drowned, marking the end of the droughts.Since then, the remains of those trees have been well preserved by the arid climate. To determine how long ago these droughts occurred, Scott is using carbon-14 to date the trees.When an organism dies it ceases to replenish carbon in its tissues and the decay of carbon 14 to nitrogen 14 changes the ratio of carbon 12 to carbon 14.
Experts can compare the ratio of carbon 12 to carbon 14 in dead material to the ratio when the organism was alive to estimate the date of its death.
technology columnist David Pogue explores how isotopes of carbon can be used to determine the age of once-living matter. The difference between them is the number of neutrons in the nucleus.