Describe process carbon dating
We can measure in the laboratory how many carbon-14 atoms are still in the skull.If we assume that the mammoth originally had the same number of carbon- 14 atoms in its bones as living animals do today (estimated at one carbon-14 atom for every trillion carbon-12 atoms), then, because we also know the radiocarbon decay rate, we can calculate how long ago the mammoth died. This dating method is similar to the principle behind an hourglass.6 The sand grains that originally filled the top bowl represent the carbon-14 atoms in the living mammoth just before it died.Radiocarbon then enters animals as they consume the plants (Figure 1b).So even we humans are radioactive because of trace amounts of radiocarbon in our bodies.By comparing the surviving amount of carbon-14 to the original amount, scientists can calculate how long ago the animal died.Since the atmosphere is composed of about 78% nitrogen,2 a lot of radiocarbon atoms are produced—in total about 16.5 pounds (7.5 kg) per year.And as far as we know, it has been forming in the earth’s upper atmosphere since the atmosphere was made back on Day Two of Creation Week (part of the expanse, or firmament, described in Genesis 1:6–8). Cosmic rays from outer space are continually bombarding the upper atmosphere of the earth, producing fast-moving neutrons (subatomic particles carrying no electric charge) (Figure 1a).1 These fast-moving neutrons collide with atoms of nitrogen-14, the most abundant element in the upper atmosphere, converting them into radiocarbon (carbon-14) atoms.
If the level is constant, living plants and animals should also maintain a constant carbon-14 level in them.Since each beta particle represents one decayed carbon-14 atom, we know how many carbon-14 atoms decay during a month.Chemists have already determined how many atoms are in a given mass of each element, such as carbon.4 So if we weigh a lump of carbon, we can calculate how many carbon atoms are in it.Although many people think radiocarbon dating is used to date rocks, it is limited to dating things that contain the element carbon and were once alive (like fossils).