Radiometric dating quiz questions
In the early years of radiocarbon dating a product’s decay was measured, but this required huge samples (e.g. Many labs now use an Accelerator Mass Spectrometer (AMS), a machine that can detect and measure the presence of different isotopes, to count the individual C atoms in a sample.This method requires less than 1g of bone, but few countries can afford more than one or two AMSs, which cost more than A0,000.The calibrated date is our “best estimate” of the sample’s actual age, but we need to be able to return to old dates and recalibrate them because new research is continually used to update the calibration curve.The second difficulty arises from the extremely low abundance of C, making it incredibly difficult to measure and extremely sensitive to contamination.Australia has two machines dedicated to radiocarbon analysis, and they are out of reach for much of the developing world.In addition, samples need to be thoroughly cleaned to remove carbon contamination from glues and soil before dating.While the lighter isotopes C has decayed that what remains can no longer be measured. In 5,730 years half of the C in the atmosphere, and therefore in plants and animals, has not always been constant.
Professor Willard Libby produced the first radiocarbon dates in 1949 and was later awarded the Nobel Prize for his efforts.
Materials such as rocks and carbon often contain small traces of radioactive isotopes.
By comparing the relative amount of the isotope with that found in nature an estimate of the materials age can be obtained. 2] '''Potassium Argon (K–Ar) Dating''' Potassium-40 is a radioactive isotope that will spontaneously decay into argon-40, another radioactive isotope.
A huge amount of work is currently underway to extend and improve the calibration curve.
In 2008 we could only calibrate radiocarbon dates until 26,000 years.
This means that although they are very similar chemically, they have different masses.