Explain one way in which archaeologists date an item found on a dig - Junior Cycle History - Question (ii) - 2009

Archaeologists often use Carbon-14 dating to determine the age of organic materials. This method relies on measuring the amount of Carbon-14, a radioactive isotope, present in the sample. As living organisms absorb Carbon-14 from the atmosphere during their lifetime, once they die, the Carbon-14 begins to decay at a known rate (half-life of about 5,730 years). By calculating the remaining amount of Carbon-14 in the sample, archaeologists can estimate when the organism died, thus providing a dating reference for the item found. This technique is particularly effective for dating materials up to about 50,000 years old.