When finding the age of an organic organism we need to consider the half-life of carbon 14 as well as the rate of decay, which is –0.693.For example, say a fossil is found that has 35% carbon 14 compared to the living sample. We can use a formula for carbon 14 dating to find the answer.Carbon is naturally in all living organisms and is replenished in the tissues by eating other organisms or by breathing air that contains carbon.
One excellent example of this is the use of radioactive carbon-14 to determine the steps involved in the photosynthesis in plants.
We know these steps because researchers followed the progress of the radioactive carbon-14 throughout the process.
Radioactive isotopes are useful for establishing the ages of various objects.
The half-life of radioactive isotopes is unaffected by any environmental factors, so the isotope acts like an internal clock.
Generally, however, they are useful either because we can detect their radioactivity or we can use the energy they release.
Radioactive isotopes are effective tracers because their radioactivity is easy to detect.The radiation emitted by some radioactive substances can be used to kill microorganisms on a variety of foodstuffs, which extends the shelf life of these products.Produce such as tomatoes, mushrooms, sprouts, and berries are irradiated with the emissions from cobalt-60 or cesium-137.So, the fossil is 8,680 years old, meaning the living organism died 8,680 years ago.Radioactive isotopes have a variety of applications.Shroud of Turin In 1989, several groups of scientists used carbon-14 dating to demonstrate that the age of the Shroud of Turin was only 600–700 y.