Final answer:
The measurement of radioactive Carbon-14 present in organic materials is the basis for radiocarbon dating, which can date artefacts up to around 60,000 years old by assessing the decay rate of Carbon-14 after the organism's death. The half-life of Carbon-14 is about 5730 years, which allows scientists to approximate the age of the object based on the remaining ratio of Carbon-14 to Carbon-12 in comparison to that ratio in the atmosphere.
Step-by-step explanation:
The organic material in sediment layers is dated by measuring the amount of radioactive Carbon-14 present. This method, known as radiocarbon dating, is utilized to determine the age of organic material that was once living. When organisms are alive, they absorb Carbon-14 and stable Carbon-12 at a certain ratio. After the organism dies, it stops absorbing Carbon-14, and this isotope begins to decay while the amount of Carbon-12 remains constant. The original ratio of Carbon-14 to Carbon-12 changes over time and, by measuring this ratio in comparison to living organisms, we can calculate the time elapsed since the organism's death.
Carbon-14 dating is most effective for dating organic artefacts between 50 and 60,000 years old. The half-life of Carbon-14 is approximately 5730 years, which means that after this period, the amount of this radioactive carbon isotope is reduced by half. By measuring the remaining Carbon-14 in a sample and comparing it to the ratio of Carbon-14 to Carbon-12 in the atmosphere, the age of the object can be estimated. This technique has revolutionized archaeology and earned its developer, Willard Libby, the 1960 Nobel Prize in Chemistry.