Carbon dating age of
Carbon-14 is also passed onto the animals that eat those plants.After death the amount of carbon-14 in the organic specimen decreases very regularly as the molecules decay.However, the principle of carbon-14 dating applies to other isotopes as well.Potassium-40 is another radioactive element naturally found in your body and has a half-life of 1.3 billion years.Thus the ratio of stable C-12 to unstable C-14, which is known in today's open environment, changes over time in an isolated specimen. As long as the tree lives, it absorbs carbon from the atmosphere in the form of carbon dioxide, both C-12 and C-14.Once the tree dies, it ceases to take in new carbon, and any C-14 present begins to decay.
That is until careful measurements revealed a significant disequalibrium. All the present C-14 would accumulate, at present rates of production and build up, in less than 30,000 years!
Carbon-14 has a half-life of 5,730 ± 40 years, meaning that every 5,700 years or so the object loses half its carbon-14.
Samples from the past 70,000 years made of wood, charcoal, peat, bone, antler or one of many other carbonates may be dated using this technique.
Other useful radioisotopes for radioactive dating include Uranium -235 (half-life = 704 million years), Uranium -238 (half-life = 4.5 billion years), Thorium-232 (half-life = 14 billion years) and Rubidium-87 (half-life = 49 billion years).
The use of various radioisotopes allows the dating of biological and geological samples with a high degree of accuracy.