Using the above equations, it is also possible for a relationship to be derived between t 1/2, τ, and λ. Derivation of the Relationship Between Half-Life Constants This means that the fossil is 11,460 years old. If an archaeologist found a fossil sample that contained 25% carbon-14 in comparison to a living sample, the time of the fossil sample's death could be determined by rearranging equation 1, since N t, N 0, and t 1/2 are known. N t is the remaining quantity after time, t The carbon-14 undergoes radioactive decay once the plant or animal dies, and measuring the amount of carbon-14 in a sample conveys information about when the plant or animal died.īelow are shown three equivalent formulas describing exponential decay: It is incorporated into plants through photosynthesis, and then into animals when they consume plants. The process of carbon-14 dating was developed by William Libby, and is based on the fact that carbon-14 is constantly being made in the atmosphere. The half-life of carbon-14 is approximately 5,730 years, and it can be reliably used to measure dates up to around 50,000 years ago. One of the most well-known applications of half-life is carbon-14 dating. The term is most commonly used in relation to atoms undergoing radioactive decay, but can be used to describe other types of decay, whether exponential or not. Half-life is defined as the amount of time it takes a given quantity to decrease to half of its initial value.

Half life in 60 seconds